Guide 1 of 3
Incrementality explainedWhat a holdout group proves and how to read lift, 8 min read
Insights
Guides and resourcesfor app retargeting.
Practical guides on incrementality, retargeting windows and iOS privacy, written for growth and UA teams.
Guides
Three guides for performance teams.
Incrementality explained
Why attributed conversions overstate what ads achieve, and how a holdout isolates the lift. Covers test designs and common mistakes.
Read the guideChoosing a retargeting window
How your app's return curve sets the right moment to reach a quiet user. Learn to read the window and when to stop.
Read the guideRetargeting after ATT
What ATT requires, what the IDFA enables and where SKAN and AdAttributionKit fit. Includes planning for iOS and Android budgets.
Read the guideGlossary
Mobile retargeting terms.
- Recency
- Time since a user last opened the app. It is the most useful single signal for deciding whether and when to reach them.
- Holdout
- A random share of an audience that sees none of a campaign's ads. Its behaviour shows what would have happened anyway.
- Lift
- The difference in outcome rate between the reached group and the holdout, often stated relative to the holdout's rate.
- Incrementality
- The share of results that advertising caused, meaning those that would not have happened without it.
- Attribution window
- The period after an ad is shown or clicked in which a conversion can be credited to it. Changing it changes reported results, not behaviour.
- Deferred deep link
- A link that remembers its destination through an install, so a new user opens the intended screen.
- Frequency cap
- A limit on how often the same user sees ads from a campaign in a set period.
- Suppression list
- Users excluded from a campaign, such as recent buyers or users who are already active.
- Bid request
- The message an app or exchange sends to buyers to offer one ad slot. It describes the slot, the app and, where permitted, the device.
- Bundle ID
- An app's unique store identifier, used in reporting to show which apps carried an ad.
- app-ads.txt
- A public file a developer publishes on their website, listing the companies authorised to sell the app's ad inventory.
- ATT
- App Tracking Transparency, Apple's framework that requires an app to ask permission before tracking a user across other companies' apps and websites.
- SKAdNetwork
- Apple's privacy-preserving attribution framework. It reports installs and limited conversion data in aggregate and after a delay, without device identifiers.
- First-price auction
- An auction in which the winner pays their bid. Most in-app programmatic inventory now sells this way.
- Bid shading
- Bidding below your true valuation in a first-price auction to avoid paying more than the slot needed.
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