How testing whether an urgency-driven subject line or a specific biblical reference leads to higher opens and engagement
Experiment ID: #195758
Luther Seminary
Experiment Summary
Timeframe: 02/08/2025 - 02/08/2025
Luther Seminary creates ebooks and digital resources to help their audience deepen their faith and biblical knowledge. Their latest ebook explores the book of Exodus, and they aimed to maximize engagement by optimizing the subject line of their promotional email to their housefile audience.
To determine what type of subject line would drive more opens and clicks, we conducted a series of A/B tests. In a prior test, we compared exclusivity-based language to a curiosity-driven subject line, finding that a curiosity-driving subject line increased opens by 9.4% with 100% statistical confidence.
For this next test, we wanted to know whether an urgency-based subject line (“Don’t miss this opportunity to deepen your faith”) or a subject line that was more specific and intriguing (“Discover the richness of Exodus”) would drive higher engagement. We hypothesized that the more specific and curiosity-driven subject line would increase opens by making the content feel more relevant and compelling to the reader.
This was a 50/50 A/B test, with half of the audience receiving the Control subject line and the other half receiving the Treatment.
Research Question
We believe that using a specific and intriguing biblical reference (“Discover the richness of Exodus”) instead of a more generic faith-based phrase (“Don’t miss this opportunity to deepen your faith”) for people viewing a content offer email in their inbox will achieve an increase in email opens because specificity and curiosity drive engagement, making the subject line feel more relevant and compelling to the reader.
Design
C: Control
Array
(
[0] => Array
(
[ID] => 70499
[id] => 70499
[title] => Control_-_"Don't_miss_this_opportunity_to_deepen_your_faith".png
[filename] => Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[filesize] => 76579
[url] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[link] => https://www.nextafter.com/experiments/how-testing-whether-an-urgency-driven-subject-line-or-a-specific-biblical-reference-leads-to-higher-opens-and-engagement/attachment/control_-_dont_miss_this_opportunity_to_deepen_your_faith-png-12/
[alt] =>
[author] => 0
[description] =>
[caption] =>
[name] => control_-_dont_miss_this_opportunity_to_deepen_your_faith-png-12
[status] => inherit
[uploaded_to] => 70426
[date] => 2025-03-07 15:42:20
[modified] => 2025-03-07 15:42:20
[menu_order] => 0
[mime_type] => image/png
[type] => image
[subtype] => png
[icon] => https://nextafter-1a91a.kxcdn.com/wp-includes/images/media/default.png
[width] => 382
[height] => 650
[sizes] => Array
(
[thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-150x150.png
[thumbnail-width] => 150
[thumbnail-height] => 150
[medium] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-176x300.png
[medium-width] => 176
[medium-height] => 300
[medium_large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[medium_large-width] => 382
[medium_large-height] => 650
[large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[large-width] => 382
[large-height] => 650
[1536x1536] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[1536x1536-width] => 382
[1536x1536-height] => 650
[2048x2048] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[2048x2048-width] => 382
[2048x2048-height] => 650
[ab-block-post-grid-landscape] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-600x400.png
[ab-block-post-grid-landscape-width] => 600
[ab-block-post-grid-landscape-height] => 400
[ab-block-post-grid-square] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-600x600.png
[ab-block-post-grid-square-width] => 600
[ab-block-post-grid-square-height] => 600
[tp-image-grid] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-700x700.png
[tp-image-grid-width] => 700
[tp-image-grid-height] => 700
[post-thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-150x150.png
[post-thumbnail-width] => 150
[post-thumbnail-height] => 150
[admin] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-29x50.png
[admin-width] => 29
[admin-height] => 50
[full] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[full-width] => 382
[full-height] => 650
[thumb_372] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-372x633.png
[thumb_372-width] => 372
[thumb_372-height] => 633
[single_post_thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-367x625.png
[single_post_thumbnail-width] => 367
[single_post_thumbnail-height] => 625
[thumb_32_32] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-19x32.png
[thumb_32_32-width] => 19
[thumb_32_32-height] => 32
[thumb_48_48] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-28x48.png
[thumb_48_48-width] => 28
[thumb_48_48-height] => 48
[thumb_64_64] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-38x64.png
[thumb_64_64-width] => 38
[thumb_64_64-height] => 64
[thumb_128_128] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-75x128.png
[thumb_128_128-width] => 75
[thumb_128_128-height] => 128
[thumb_122_67] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-39x67.png
[thumb_122_67-width] => 39
[thumb_122_67-height] => 67
[thumb_153_153] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-90x153.png
[thumb_153_153-width] => 90
[thumb_153_153-height] => 153
[thumb_130_163] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-96x163.png
[thumb_130_163-width] => 96
[thumb_130_163-height] => 163
[thumb_232_177] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-104x177.png
[thumb_232_177-width] => 104
[thumb_232_177-height] => 177
[thumb_272_325] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[thumb_272_325-width] => 382
[thumb_272_325-height] => 650
[thumb_271_346] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-203x346.png
[thumb_271_346-width] => 203
[thumb_271_346-height] => 346
[thumb_271_271] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-159x271.png
[thumb_271_271-width] => 159
[thumb_271_271-height] => 271
[thumb_272_172] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-101x172.png
[thumb_272_172-width] => 101
[thumb_272_172-height] => 172
[thumb_372_461] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-271x461.png
[thumb_372_461-width] => 271
[thumb_372_461-height] => 461
[thumb_372_500] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-294x500.png
[thumb_372_500-width] => 294
[thumb_372_500-height] => 500
[thumb_385_270] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-159x270.png
[thumb_385_270-width] => 159
[thumb_385_270-height] => 270
[thumb_416_241] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-142x241.png
[thumb_416_241-width] => 142
[thumb_416_241-height] => 241
[thumb_448_410] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-241x410.png
[thumb_448_410-width] => 241
[thumb_448_410-height] => 410
[thumb_448_410_retina] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[thumb_448_410_retina-width] => 382
[thumb_448_410_retina-height] => 650
[thumb_574_382] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-224x382.png
[thumb_574_382-width] => 224
[thumb_574_382-height] => 382
[thumb_776_395] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-232x395.png
[thumb_776_395-width] => 232
[thumb_776_395-height] => 395
) ) [1] => Array
(
[ID] => 70500
[id] => 70500
[title] => Treatment_-_"Discover_the_richness_of_Exodus".png
[filename] => Treatment_-_Discover_the_richness_of_Exodus-11.png
[filesize] => 73614
[url] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[link] => https://www.nextafter.com/experiments/how-testing-whether-an-urgency-driven-subject-line-or-a-specific-biblical-reference-leads-to-higher-opens-and-engagement/attachment/treatment_-_discover_the_richness_of_exodus-png-12/
[alt] =>
[author] => 0
[description] =>
[caption] =>
[name] => treatment_-_discover_the_richness_of_exodus-png-12
[status] => inherit
[uploaded_to] => 70426
[date] => 2025-03-07 15:42:22
[modified] => 2025-03-07 15:42:22
[menu_order] => 0
[mime_type] => image/png
[type] => image
[subtype] => png
[icon] => https://nextafter-1a91a.kxcdn.com/wp-includes/images/media/default.png
[width] => 384
[height] => 653
[sizes] => Array
(
[thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-150x150.png
[thumbnail-width] => 150
[thumbnail-height] => 150
[medium] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-176x300.png
[medium-width] => 176
[medium-height] => 300
[medium_large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[medium_large-width] => 384
[medium_large-height] => 653
[large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[large-width] => 384
[large-height] => 653
[1536x1536] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[1536x1536-width] => 384
[1536x1536-height] => 653
[2048x2048] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[2048x2048-width] => 384
[2048x2048-height] => 653
[ab-block-post-grid-landscape] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-600x400.png
[ab-block-post-grid-landscape-width] => 600
[ab-block-post-grid-landscape-height] => 400
[ab-block-post-grid-square] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-600x600.png
[ab-block-post-grid-square-width] => 600
[ab-block-post-grid-square-height] => 600
[tp-image-grid] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-700x700.png
[tp-image-grid-width] => 700
[tp-image-grid-height] => 700
[post-thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-150x150.png
[post-thumbnail-width] => 150
[post-thumbnail-height] => 150
[admin] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-29x50.png
[admin-width] => 29
[admin-height] => 50
[full] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[full-width] => 384
[full-height] => 653
[thumb_372] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-372x633.png
[thumb_372-width] => 372
[thumb_372-height] => 633
[single_post_thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-368x625.png
[single_post_thumbnail-width] => 368
[single_post_thumbnail-height] => 625
[thumb_32_32] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-19x32.png
[thumb_32_32-width] => 19
[thumb_32_32-height] => 32
[thumb_48_48] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-28x48.png
[thumb_48_48-width] => 28
[thumb_48_48-height] => 48
[thumb_64_64] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-38x64.png
[thumb_64_64-width] => 38
[thumb_64_64-height] => 64
[thumb_128_128] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-75x128.png
[thumb_128_128-width] => 75
[thumb_128_128-height] => 128
[thumb_122_67] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-39x67.png
[thumb_122_67-width] => 39
[thumb_122_67-height] => 67
[thumb_153_153] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-90x153.png
[thumb_153_153-width] => 90
[thumb_153_153-height] => 153
[thumb_130_163] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-96x163.png
[thumb_130_163-width] => 96
[thumb_130_163-height] => 163
[thumb_232_177] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-104x177.png
[thumb_232_177-width] => 104
[thumb_232_177-height] => 177
[thumb_272_325] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-382x650.png
[thumb_272_325-width] => 382
[thumb_272_325-height] => 650
[thumb_271_346] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-203x346.png
[thumb_271_346-width] => 203
[thumb_271_346-height] => 346
[thumb_271_271] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-159x271.png
[thumb_271_271-width] => 159
[thumb_271_271-height] => 271
[thumb_272_172] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-101x172.png
[thumb_272_172-width] => 101
[thumb_272_172-height] => 172
[thumb_372_461] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-271x461.png
[thumb_372_461-width] => 271
[thumb_372_461-height] => 461
[thumb_372_500] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-294x500.png
[thumb_372_500-width] => 294
[thumb_372_500-height] => 500
[thumb_385_270] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-159x270.png
[thumb_385_270-width] => 159
[thumb_385_270-height] => 270
[thumb_416_241] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-142x241.png
[thumb_416_241-width] => 142
[thumb_416_241-height] => 241
[thumb_448_410] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-241x410.png
[thumb_448_410-width] => 241
[thumb_448_410-height] => 410
[thumb_448_410_retina] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[thumb_448_410_retina-width] => 384
[thumb_448_410_retina-height] => 653
[thumb_574_382] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-225x382.png
[thumb_574_382-width] => 225
[thumb_574_382-height] => 382
[thumb_776_395] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-232x395.png
[thumb_776_395-width] => 232
[thumb_776_395-height] => 395
) ) )
T1: Treatment 1
Array
(
[0] => Array
(
[ID] => 70499
[id] => 70499
[title] => Control_-_"Don't_miss_this_opportunity_to_deepen_your_faith".png
[filename] => Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[filesize] => 76579
[url] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[link] => https://www.nextafter.com/experiments/how-testing-whether-an-urgency-driven-subject-line-or-a-specific-biblical-reference-leads-to-higher-opens-and-engagement/attachment/control_-_dont_miss_this_opportunity_to_deepen_your_faith-png-12/
[alt] =>
[author] => 0
[description] =>
[caption] =>
[name] => control_-_dont_miss_this_opportunity_to_deepen_your_faith-png-12
[status] => inherit
[uploaded_to] => 70426
[date] => 2025-03-07 15:42:20
[modified] => 2025-03-07 15:42:20
[menu_order] => 0
[mime_type] => image/png
[type] => image
[subtype] => png
[icon] => https://nextafter-1a91a.kxcdn.com/wp-includes/images/media/default.png
[width] => 382
[height] => 650
[sizes] => Array
(
[thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-150x150.png
[thumbnail-width] => 150
[thumbnail-height] => 150
[medium] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-176x300.png
[medium-width] => 176
[medium-height] => 300
[medium_large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[medium_large-width] => 382
[medium_large-height] => 650
[large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[large-width] => 382
[large-height] => 650
[1536x1536] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[1536x1536-width] => 382
[1536x1536-height] => 650
[2048x2048] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[2048x2048-width] => 382
[2048x2048-height] => 650
[ab-block-post-grid-landscape] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-600x400.png
[ab-block-post-grid-landscape-width] => 600
[ab-block-post-grid-landscape-height] => 400
[ab-block-post-grid-square] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-600x600.png
[ab-block-post-grid-square-width] => 600
[ab-block-post-grid-square-height] => 600
[tp-image-grid] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-700x700.png
[tp-image-grid-width] => 700
[tp-image-grid-height] => 700
[post-thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-150x150.png
[post-thumbnail-width] => 150
[post-thumbnail-height] => 150
[admin] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-29x50.png
[admin-width] => 29
[admin-height] => 50
[full] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[full-width] => 382
[full-height] => 650
[thumb_372] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-372x633.png
[thumb_372-width] => 372
[thumb_372-height] => 633
[single_post_thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-367x625.png
[single_post_thumbnail-width] => 367
[single_post_thumbnail-height] => 625
[thumb_32_32] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-19x32.png
[thumb_32_32-width] => 19
[thumb_32_32-height] => 32
[thumb_48_48] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-28x48.png
[thumb_48_48-width] => 28
[thumb_48_48-height] => 48
[thumb_64_64] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-38x64.png
[thumb_64_64-width] => 38
[thumb_64_64-height] => 64
[thumb_128_128] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-75x128.png
[thumb_128_128-width] => 75
[thumb_128_128-height] => 128
[thumb_122_67] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-39x67.png
[thumb_122_67-width] => 39
[thumb_122_67-height] => 67
[thumb_153_153] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-90x153.png
[thumb_153_153-width] => 90
[thumb_153_153-height] => 153
[thumb_130_163] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-96x163.png
[thumb_130_163-width] => 96
[thumb_130_163-height] => 163
[thumb_232_177] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-104x177.png
[thumb_232_177-width] => 104
[thumb_232_177-height] => 177
[thumb_272_325] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[thumb_272_325-width] => 382
[thumb_272_325-height] => 650
[thumb_271_346] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-203x346.png
[thumb_271_346-width] => 203
[thumb_271_346-height] => 346
[thumb_271_271] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-159x271.png
[thumb_271_271-width] => 159
[thumb_271_271-height] => 271
[thumb_272_172] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-101x172.png
[thumb_272_172-width] => 101
[thumb_272_172-height] => 172
[thumb_372_461] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-271x461.png
[thumb_372_461-width] => 271
[thumb_372_461-height] => 461
[thumb_372_500] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-294x500.png
[thumb_372_500-width] => 294
[thumb_372_500-height] => 500
[thumb_385_270] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-159x270.png
[thumb_385_270-width] => 159
[thumb_385_270-height] => 270
[thumb_416_241] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-142x241.png
[thumb_416_241-width] => 142
[thumb_416_241-height] => 241
[thumb_448_410] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-241x410.png
[thumb_448_410-width] => 241
[thumb_448_410-height] => 410
[thumb_448_410_retina] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11.png
[thumb_448_410_retina-width] => 382
[thumb_448_410_retina-height] => 650
[thumb_574_382] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-224x382.png
[thumb_574_382-width] => 224
[thumb_574_382-height] => 382
[thumb_776_395] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Control_-_Dont_miss_this_opportunity_to_deepen_your_faith-11-232x395.png
[thumb_776_395-width] => 232
[thumb_776_395-height] => 395
) ) [1] => Array
(
[ID] => 70500
[id] => 70500
[title] => Treatment_-_"Discover_the_richness_of_Exodus".png
[filename] => Treatment_-_Discover_the_richness_of_Exodus-11.png
[filesize] => 73614
[url] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[link] => https://www.nextafter.com/experiments/how-testing-whether-an-urgency-driven-subject-line-or-a-specific-biblical-reference-leads-to-higher-opens-and-engagement/attachment/treatment_-_discover_the_richness_of_exodus-png-12/
[alt] =>
[author] => 0
[description] =>
[caption] =>
[name] => treatment_-_discover_the_richness_of_exodus-png-12
[status] => inherit
[uploaded_to] => 70426
[date] => 2025-03-07 15:42:22
[modified] => 2025-03-07 15:42:22
[menu_order] => 0
[mime_type] => image/png
[type] => image
[subtype] => png
[icon] => https://nextafter-1a91a.kxcdn.com/wp-includes/images/media/default.png
[width] => 384
[height] => 653
[sizes] => Array
(
[thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-150x150.png
[thumbnail-width] => 150
[thumbnail-height] => 150
[medium] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-176x300.png
[medium-width] => 176
[medium-height] => 300
[medium_large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[medium_large-width] => 384
[medium_large-height] => 653
[large] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[large-width] => 384
[large-height] => 653
[1536x1536] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[1536x1536-width] => 384
[1536x1536-height] => 653
[2048x2048] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[2048x2048-width] => 384
[2048x2048-height] => 653
[ab-block-post-grid-landscape] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-600x400.png
[ab-block-post-grid-landscape-width] => 600
[ab-block-post-grid-landscape-height] => 400
[ab-block-post-grid-square] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-600x600.png
[ab-block-post-grid-square-width] => 600
[ab-block-post-grid-square-height] => 600
[tp-image-grid] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-700x700.png
[tp-image-grid-width] => 700
[tp-image-grid-height] => 700
[post-thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-150x150.png
[post-thumbnail-width] => 150
[post-thumbnail-height] => 150
[admin] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-29x50.png
[admin-width] => 29
[admin-height] => 50
[full] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[full-width] => 384
[full-height] => 653
[thumb_372] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-372x633.png
[thumb_372-width] => 372
[thumb_372-height] => 633
[single_post_thumbnail] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-368x625.png
[single_post_thumbnail-width] => 368
[single_post_thumbnail-height] => 625
[thumb_32_32] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-19x32.png
[thumb_32_32-width] => 19
[thumb_32_32-height] => 32
[thumb_48_48] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-28x48.png
[thumb_48_48-width] => 28
[thumb_48_48-height] => 48
[thumb_64_64] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-38x64.png
[thumb_64_64-width] => 38
[thumb_64_64-height] => 64
[thumb_128_128] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-75x128.png
[thumb_128_128-width] => 75
[thumb_128_128-height] => 128
[thumb_122_67] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-39x67.png
[thumb_122_67-width] => 39
[thumb_122_67-height] => 67
[thumb_153_153] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-90x153.png
[thumb_153_153-width] => 90
[thumb_153_153-height] => 153
[thumb_130_163] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-96x163.png
[thumb_130_163-width] => 96
[thumb_130_163-height] => 163
[thumb_232_177] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-104x177.png
[thumb_232_177-width] => 104
[thumb_232_177-height] => 177
[thumb_272_325] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-382x650.png
[thumb_272_325-width] => 382
[thumb_272_325-height] => 650
[thumb_271_346] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-203x346.png
[thumb_271_346-width] => 203
[thumb_271_346-height] => 346
[thumb_271_271] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-159x271.png
[thumb_271_271-width] => 159
[thumb_271_271-height] => 271
[thumb_272_172] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-101x172.png
[thumb_272_172-width] => 101
[thumb_272_172-height] => 172
[thumb_372_461] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-271x461.png
[thumb_372_461-width] => 271
[thumb_372_461-height] => 461
[thumb_372_500] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-294x500.png
[thumb_372_500-width] => 294
[thumb_372_500-height] => 500
[thumb_385_270] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-159x270.png
[thumb_385_270-width] => 159
[thumb_385_270-height] => 270
[thumb_416_241] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-142x241.png
[thumb_416_241-width] => 142
[thumb_416_241-height] => 241
[thumb_448_410] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-241x410.png
[thumb_448_410-width] => 241
[thumb_448_410-height] => 410
[thumb_448_410_retina] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11.png
[thumb_448_410_retina-width] => 384
[thumb_448_410_retina-height] => 653
[thumb_574_382] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-225x382.png
[thumb_574_382-width] => 225
[thumb_574_382-height] => 382
[thumb_776_395] => https://nextafter-1a91a.kxcdn.com/wp-content/uploads/Treatment_-_Discover_the_richness_of_Exodus-11-232x395.png
[thumb_776_395-width] => 232
[thumb_776_395-height] => 395
) ) )
Results
| Treatment Name | Open Rate | Relative Difference | Confidence | |
|---|---|---|---|---|
| C: | Control | 23.8% | ||
| T1: | Treatment 1 | 22.9% | -3.8% | 95.6% |
This experiment has a required sample size of 16,551 in order to be valid. Since the experiment had a total sample size of 35,061, and the level of confidence is above 95% the experiment results are valid.
Flux Metrics Affected
The Flux Metrics analyze the three primary metrics that affect revenue (traffic, conversion rate, and average gift). This experiment produced the following results:
3.8% decrease in traffic
× 0% increase in conversion rate
× 0% increase in average gift
Key Learnings
This test produced unexpected but valuable insights about the relationship between subject line messaging and user engagement.
While the Control subject line (“Don’t miss this opportunity to deepen your faith”) generated more opens, the Treatment subject line (“Discover the richness of Exodus”) resulted in fewer opens (a 3.8% decrease) but led to a 24.5% increase in email clicks, with a 98.4% statistical level of confidence.
This suggests that while urgency-driven language in the Control created a stronger initial impulse to open the email, the specificity of the Treatment subject line attracted a more engaged audience—those who opened were more likely to click through to the content.
Psychologically, this aligns with two key principles:
- FOMO (Fear of Missing Out) and urgency – The Control subject line may have driven more opens by making the email feel time-sensitive and broadly relevant.
- Relevance and commitment – The Treatment subject line set clearer expectations about the content, likely attracting recipients who were already interested in the topic, leading to higher engagement post-open.