Start collecting user data after app has already been live for a while

Question

I have a basic question about a facebook app I am building. In the first phase, we are building the app so that it doesn't collect any user information, thus keeping the user from having to click the "allow" button to use the app. However, we are considering adding features to the app later on that would require user information. I am just curious if it is a good idea to build it like this, or if we should just collect user information from the start. Would users think it is strange for an app to start collecting data after the app is already live? Any advice is appreciated. Thanks!

Answer 1

No it's not a bad idea. Actually Facebook recommends only asking for a permission when needed:

As a best practice, you should only request extended permissions at reasonable times when the user engages with features that would require their use. For example, if you are asking the user for the publish_stream permission in order to create a custom share UI, the user will better understand the context behind your request if presented with the permission while interacting with the app's share functionality.

Please DO visit the document I linked to.