A 1,000% lift in promo conversion through disciplined split testing

The challenge

Promotional rate campaigns are a steady revenue lever for a bank, and small gains in response compound fast across millions of sends. Our client wanted more incremental response from each campaign, and it wanted those gains to be provable.

The existing emails carried years of accumulated clutter, and too many of them were designed for a desktop inbox while most customers were reading on their phones.

What we did

Trellist built a structured A/B and multivariate testing program around the campaigns, with every test tied to a clear hypothesis.

• Hypothesis-led tests. Each split test grew out of what prior creative and campaign results were telling us, so every round built on the last.
• Mobile-first simplification. We streamlined the emails to cut clutter and designed for the mobile reading experience first.
• Motion as a tactic. We introduced animation to draw the eye and encourage engagement and interaction with the offer.
• A new champion. The winning creative became the new control and proved strong enough that other campaigns adopted it.