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Measurement and attribution

What is mobile attribution?

Short answer

Mobile attribution is working out which ad, campaign or link brought an app install or an in-app action, such as a sign-up or a purchase. It can be deterministic, based on a click ID, the install referrer or the link that opened the app, or probabilistic, based on statistical matching.

Who does it

For paid ads, mobile measurement partners (MMPs) such as AppsFlyer and Adjust collect clicks and installs, decide which source gets the credit and report back to the ad networks. Without an MMP, store reports, App Store campaign links and the Google Play install referrer already answer a lot of questions.

What changed on iOS

Since iOS 14.5 in 2021, App Tracking Transparency requires an app to ask permission before it links its data with other companies’ apps and websites for advertising. Apple’s own frameworks, SKAdNetwork and the newer AdAttributionKit, report ad results without identifying the person.

Apple also doesn’t allow deriving data from a device to identify it, so matching installs by device signals is off the table on iPhone. Deterministic signals carry more weight than ever.

Read moreMobile Attribution in 2026: What Still Works After Privacy Sandbox DiedA map of the measurement methods that still work in 2026, and the order in which to rely on them.

Related terms

  • Fingerprinting

    Fingerprinting matches an app install to an earlier click by combining signals such as IP address, device model and operating system version, instead of a real identifier. Apple’s rules forbid fingerprinting for tracking, even when the user has agreed to tracking, and privacy regulators look at it closely.

  • Install referrer

    The install referrer is the referrer value from a Google Play link, which Google Play passes to your app after installation through the Play Install Referrer API. The app reads it once on first run, and it stays available for 90 days. It gives deterministic install attribution on Android; the App Store has no equivalent.

  • Postback

    A postback is a server-to-server message that reports an app install or an in-app event, such as a purchase, to an ad network or to your own server. When it goes to your own server, it’s usually called a webhook. Postbacks are often signed, so the receiver can check they are genuine.

All glossary terms

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