The Google Play Install Referrer

What the Install Referrer returns

Google describes the Install Referrer API as a way to securely retrieve referral content from Google Play.^[1] The app asks Google Play, and Google Play answers with a small set of fields.

The two timestamps are given both client-side and server-side.^[1] The last two fields come from the same documentation.^[1] Devices with a Google Play app version of 8.3.73 or later have access to the API automatically.^[1]

How an MMP turns it into a match

1. A person taps an ad. The tracking link records the click and sends them to the Play Store with a referrer value attached to the store address.
2. Google Play keeps that value while the app downloads.
3. On first open, the MMP's SDK asks for the install referrer and receives the URL and the timestamps.
4. The MMP finds the click that carries the same value and credits it, if the click is inside the lookback window.

Because the value at the click and the value at first open are the same string, this is a deterministic match. The comparison with other methods is in deterministic versus probabilistic matching.

What the timestamps are good for

The click time and the install-begin time let an MMP check that events happened in a believable order. A click that is recorded after the download had already started cannot have caused the install. A claimed click with a very long gap before the install deserves less trust than a recent one. These checks are one input to fraud rules, which the fraud prevention basics guide explains.

Where the referrer does not help

• Ad views. The referrer describes a click that led to the store. An ad that was only seen leaves no referrer, so view-through attribution relies on other data.
• Installs from outside Google Play. The content comes from Google Play, so other Android stores are not covered.
• People who already have the app. The API describes an install. An ad that brings an existing user back is a re-engagement and is matched another way.
• iOS. The API belongs to Google Play, and iOS installs are matched in other ways. See how iOS and Android attribution differ.

What to check in your own app

Ask your developer three things. First, is the MMP's Android SDK reading the install referrer? Second, does a test install from a tracking link show up in the MMP's test console with the right campaign? Third, do your store links pass through a redirect or a shortener that might strip the referrer value? If a test install arrives as organic, check the third question first.