I think I implemented the Facebook Android SDK properly but when I check the number of events in Facebook Events Manager, I see a very low (and clearly wrong) number of installs compared to the number of ActivateApp events. See the picture below:

Why do I get such an inconsistent number of installs ?

By the way, my number of ‘Activate app’ events over one month is 20 times lower than my number of active monthly users ; any idea how is that possible ?

Thanks for your help.