Here are various reasons for deviations in reporting data. Please find a few below:
- In case you (advertiser) did user acquisition campaigns with other companies before there might be some users that installed the app through us that had installed the app before. We could only detect and prevent that by means of a tracking SDK.
- Google reports unique user installs whereas we provide unique device installs - the latter number is usually greater.
- Differences in the methodology how Google and we report a user's country.