Ok, thinking you have already your app live and then you decide to start tracking your app statistics with EMMA, what will your old users happen with? When will EMMA start to track them? How can you identify theses users in your app statistics?
When you install a new SDK you have to notice that all your older version users will appear as new users when they update the app. This is a common and inevitable process that allow detect and save all users tracked, the ones who really will be new users and the ones who will not.
Based on that, keep in mind your first days EMMA analysis, where you will find more new users percentage than in future periods.
As you can see in the visual example an app with an x number of users exisistents that integrate EMMA SDK will start counting these amount as new users when they open the new version updated. Old traffic and new traffic you could generate via the app markets will be summed as new users.
Unfortunately the separation between real new users and old ones is not possible with the current technologies so, in order to achieve a not devalued data, we recommend wait at least 15 days from your update app version to consider your new users traffic as a real flow.