Playbook: A/B test your affiliate buttons without faking statistical significance

Playbook: A/B test your affiliate buttons without faking statistical significance

Most review-site A/B tests (Nelio / VWO / Google Optimize successors) lie to you because the operator stops the moment the variant looks good.

Run it right:
— Define the metric BEFORE: click-to-outbound rate, not pageviews. Conversion happens at the merchant, so track the click as your proxy.
— Calculate sample size up front. Below ~350 clicks per variant you cannot trust a button-color result. Use a calculator, not vibes.
— Test ONE element per round: copy OR color OR placement. Changing three means you learn nothing.
— Run full weeks. Weekend buyers behave differently; a Tue-to-Fri test is biased.
— Don't peek-and-stop. Set the end date and honor it, or your "19% lift" is noise.

Gotcha: testing button copy on a page that gets seasonal traffic ("best gifts") contaminates the result with intent shifts no tool flags.

Bottom line: pre-set sample size, one variable, full weeks, no early stop. A button test under 350 clicks/variant is a coin flip with extra steps.