The least disruptive way for them to begin to capitalize on the money that 3rd party developers are making off of them, in my opinion, is to introduce an amazon

The least disruptive way for them to begin to capitalize on the money that 3rd party developers are making off of them, in my opinion, is to introduce an amazon type model, where the first 3000 (for example) api calls are free, and then they're charged at 0.01 cents per call or something. Just layer on a small api tax, so anybody actually making money can continue to do so, but those who aren't will go away and unload the system. Giving away some free api calls lets innovation and experimentation continue as well.