Conversion lift explained: how holdout tests measure the incremental impact of ads
· 27h ago · Originally reported by PPC Land
Conversion lift testing measures the extra conversions an ad actually causes by comparing a randomised group of exposed users against a holdout group that did not see the ad. An explainer outlines how major platforms run these experiments and the shortcomings that can limit how reliable the results are.
Why it matters
Lift measurement is how advertisers decide whether ads drive real business results rather than conversions that would have happened anyway, so weaknesses in the method directly affect where budgets go.
Explain it like I’m new here
It's like testing if a shop's new poster works by comparing what customers who saw it bought with what customers who never saw it bought.
Terms in this story
Conversion
A conversion is a valuable action that an advertiser wants people to take after seeing or clicking an ad, such as a purchase, sign-up, app install, call or form submission.
Holdout group
A holdout group is a randomly chosen portion of an audience deliberately not shown a campaign's ads, used as a baseline to measure the ads' true incremental effect.
Creative
A creative is the actual ad content a person sees or hears, such as an image, video, audio spot, HTML5 animation or native text, delivered into an ad slot.
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