I'm seeing that this is a longer conversation, but consider this simple example. Facebook ad rates have dropped significantly from their early days. When people are communicating in an application (which is all Facebook really is), they are not in the mood to buy/convert. So, if you are receiving income, great, but I doubt it will be sustainable. Take a look at the ads you get and see if you get re-buys.
Anyways, please don't take this as harsh. This is probably one of the hardest problems for a publisher to solve. Twitter is just trying to figure it out right now.