How to determine the source of an app purchase on GooglePlay?

Question

Java

We have:
- 2 applications on GP (free and paid version)
- sponsor advertising the application
Task:
- to find out what sales were motivated by this sponsor's advertising.

Answer 1

By using Advertising ID
https://developer.android.com/google/play-services...
Sponsor registers which IDs clicked on an ad and writes it to the database, applications check the current ID on the first run and see if the user clicked on the ad.