To build a profitable Android application, we need to know about monetization, login and social media features, deployment and support for legacy devices (including making a decision based on market shares), building a usable interface for phones AND tablets, localization to different languages (depending on market shares), etc.
A lot more of these "ecosystem concerns" come to mind. These are vital to publishing our own applications and making a living out of it. Unfortunately, the information is scattered all over the web.
Do you have any advice to help us through these issues?