Custom Content Block Testing
Test promoted products, featured collections, and editorial blocks
"Personalised picks" outperformed "Staff favourites" and "Trending now" blocks. Revenue per exposure: £0.42 vs £0.31 (control). +£4,400 additional revenue across 40K recipients. 94% confidence.
Beyond subject lines, hero blocks and CTAs, most emails carry content blocks that showcase products, collections or editorial content. These blocks drive much of the click-through and revenue in a campaign, yet they are rarely tested in any systematic way, which leaves the largest revenue lever in the email running on a guess.
What counts as a custom content block?
Any modular section of your email that can be swapped between variants:
- Promoted products: a curated grid of items you want to highlight.
- Featured collections: “New arrivals”, “Back in stock”, “Editor’s picks”.
- Social proof blocks: customer reviews, user content or bestsellers.
- Editorial content: brand storytelling, how-to guides, lifestyle imagery.
- Offer layouts: different ways to present the same promotion, such as a single hero product against a multi-product grid.
How liftstack handles content block testing
- Create a snippet for each content block position in your email template.
- Add two or three variants with different content strategies, for example personalised recommendations against an editorially curated set against trending items.
- Set revenue per exposure or conversion rate as your primary metric.
- Read results after a single campaign send for audiences of 30,000 and above.
Why content blocks are high-leverage
Subject lines decide whether someone opens. Hero blocks set the tone. Content blocks are where browsing turns into buying. A well-chosen product grid or collection feature can shift revenue per send meaningfully, and because these blocks appear in every campaign, the improvement compounds across every send.
Getting started
Take your highest-revenue email template and find the main product or collection block. Create three variants: your current approach as the control, a personalisation-driven alternative and a curation-driven alternative. One campaign is usually enough to get a clear signal on which strategy your audience prefers.