Ready to get out of the Promotions folder? Get started free
Back to Home
Case StudyG Fuel

The Official Energy Drink of Esports increased cart abandonment revenue by 435% with Mailtail.

125Countries
1B+Social Followers
100M+Emails Tested
+147%
Open Rate (Product Launch)
+435%
Revenue (Cart Abandonment)
100%
Statistical Significance

Klaviyo A/B split tests, September 2025 - January 2026

Want results like these? See how Mailtail can work for your brand.

The Problem

Promotions Tab Was Killing Revenue

G Fuel's emails landed in Gmail's Promotions tab—buried with hundreds of other marketing emails. For limited-edition flavor drops that sell out in hours, invisibility meant lost sales.

24.2%
Open rate on product launches
~31%
Open rate on cart abandonment
Low
Revenue per abandonment flow
The Solution

Unique Code That Gmail Can't Pattern-Match

Mailtail generates completely unique code for each merchant. Not identical snippets copied across clients—actual unique variations Gmail can't detect and auto-flag as promotional.

Every merchant gets unique code variations
No detectable patterns across domains
Works alongside existing email fundamentals
2-minute Klaviyo integration

A/B Test Results

Every flow tested. Every flow improved. Real Klaviyo data.

Product Launch Campaign

Highest volume test
Product Launch A/B Test
Stat Sig

320K+ total sends (160K per variation)

MetricControlMailtailLift
Open Rate24.18%59.83%+147%
Click Rate0.10%0.19%+90%
Winner: Mailtail

Welcome Flow

First impression
Welcome Email A/B Test

1.4K total sends

MetricControlMailtailLift
Open Rate34.26%44.30%+29%
Click Rate2.78%3.53%+27%
Revenue--+91%
Winner: Mailtail

Cart Abandonment Flows

High-intent buyers
Cart Abandonment Test #1

7.2K total sends

MetricControlMailtailLift
Open Rate30.63%43.85%+43%
Click Rate1.08%1.71%+58%
Revenue--+1,531%
Winner: Mailtail
Cart Abandonment Test #2

4.9K total sends

MetricControlMailtailLift
Open Rate30.39%43.62%+44%
Click Rate1.13%1.81%+60%
Revenue--+1,140%
Winner: Mailtail
Cart Abandonment Test #3

4.5K total sends

MetricControlMailtailLift
Open Rate32.66%49.87%+53%
Click Rate1.87%3.13%+67%
Revenue--+435%
Winner: Mailtail
Cart Abandonment Test #4

259 total sends

MetricControlMailtailLift
Open Rate26.19%54.86%+110%
Click Rate0.00%4.00%-
Revenue$0>$0-
Winner: Mailtail

Checkout Abandonment Flows

Highest intent
Checkout Abandonment Test #1

1.1K total sends

MetricControlMailtailLift
Open Rate31.85%48.57%+53%
Click Rate1.03%1.98%+92%
Revenue--+1,053%
Winner: Mailtail
Checkout Abandonment Test #2

147 total sends

MetricControlMailtailLift
Open Rate27.45%45.83%+67%
Click Rate0.00%4.17%-
Revenue--+596%
Winner: Mailtail

Campaign-Level Impact

Comparing similar promotional campaigns with and without Mailtail

BOGO Campaign Comparison

Similar promotional campaigns, one with Mailtail, one without

MetricWithoutWith MailtailLift
Open Rate31.69%54.14%+71%
Click Rate0.69%1.21%+75%
Order Rate0.12%0.23%+92%
Revenue/Recipient$0.09$0.16+78%

+48% total revenue lift from a single campaign

The Bottom Line

Consistent improvements across every email type tested

+58%
Avg. Open Rate Lift
+93%
Avg. Click Rate Lift
+48%
Campaign Revenue Lift
100M+
Emails Tested

Highest gains came from cart and checkout abandonment—the customers closest to buying saw the biggest lift.

Ready for results like these?

Join G Fuel and other leading brands using Mailtail to land in Primary and drive more revenue.

2-minute setup. No credit card required.

All data from Klaviyo A/B split tests conducted September 2025 - January 2026. Control groups received standard emails without Mailtail. Test groups received Mailtail-optimized emails. Results may vary based on industry, list quality, and email practices.