Install

How it works

The app store counts downloads. The MMP cannot see that moment, because its SDK is part of the app and only runs once the app is opened. On first open the SDK sends one message to the MMP. The MMP records the install, looks for a click that led to it inside the lookback window and assigns a source. Airbridge, for example, defines installs in its reports as first app opens.^[1]

When it matters

The definition explains two gaps that confuse new teams.

• Store downloads are higher than MMP installs. Some people download an app and never open it. The store counts them and the MMP does not.
• The dates do not line up. A person can download on Friday and open on Monday. The store reports Friday and the MMP reports Monday.

Reinstalls are a third case. A person who deleted the app and returns is usually reported separately from a new install, and each MMP has its own rule for when that happens. Check the rule before you compare totals.

How it relates to attribution

The install is the event that every other number hangs on. Purchases and sign-ups are credited to the source of the install that came before them, and cost per install divides spend by this count. An install with no matching click becomes an organic install. When your install count and an ad platform's count disagree, the cause is often a different definition of the same word, as described under discrepancy.