Click ID

How it works

When the click happens, the ad platform or the MMP creates a random string and saves it with the campaign, the ad and the time. The same string is added to the address the person is sent to. From there it has to reach the app. On Android it can ride inside the store referrer, as described in the Google Play Install Referrer guide. When the app is already installed, it arrives inside the link that opens the app.

Once the SDK has the value, the MMP looks it up and finds one click. Nothing is inferred.

When it matters

A click ID matters in two directions.

• Inbound: it gives the MMP a deterministic match without a device identifier.
• Outbound: when the MMP reports a conversion to the ad platform in a postback, including the platform's own click ID lets the platform connect the result to its own record of the click.

It also matters on the web. A landing page that drops the value from the address, through a redirect or a link shortener, breaks the chain before the store. The related idea for websites is covered under UTM parameters, which label a campaign but do not identify a single click.

How it relates to attribution

A click ID is one of the carriers that make a match deterministic; the comparison is in deterministic versus probabilistic matching. It identifies a click and says nothing by itself about who the person is. It expires in practice when the lookback window does, because a click that can no longer win has no use in a match.