Deezer invested significantly in mobile download campaigns as a way to acquire users for their freemium service. But they found that not enough of the users who downloaded their service were converting to subscription users. Additionally, users who downloaded the app would often become inactive after a few months or weeks. Deezer needed a way to engage and convert freemium users to their Premium+ service.
Criteo enabled Deezer to run in-app ad campaigns for their key segments: dormant and active users. This is done by uniquely identifying users on their mobile devices and building a profile that tracks their events.