Banner ad A/B testing: one useful question at a time
Plan a focused experiment, choose the primary outcome, keep the comparison fair, and report uncertainty honestly.
Read the field noteBanner ads | Ad sizes | Display advertising | Adtech | Affiliate marketing | Lead generation
Field Notes / Topic
Explore composition, message hierarchy, format choice, and creative testing. A useful ad communicates one honest promise and gives the visitor a clear next step.

Plan a focused experiment, choose the primary outcome, keep the comparison fair, and report uncertainty honestly.
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Start with a clear offer, choose a practical format set, and connect every click to a campaign you can evaluate.
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Build readable mobile banners with a focused promise, an honest action, and a destination that works on a phone.
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A practical guide to rectangles, leaderboards, tall units, and mobile banners—with a better way to plan your format set.
Read the field noteStart with the field note that best matches your current decision. Use its examples to inspect the brief, creative, destination, or reporting process in front of you. Keep the assumptions visible and adapt the method to your own campaign rather than treating a worked example as a performance target.
Then open the related reference pages for formats, terminology, or a practical handoff checklist. Save the version you use and record the next question your review needs to answer.