It all reminds me of this post: http://daltoncaldwell.com/dear-mark-zuckerberg

Facebook is trying to make the platform too good for startups to resist building on. By the time something built on the platform emerges as a success, Facebook can either heavy-hand them into an acquisition, or lock them out and take away their momentum.

It's as though they are trying to get everyone else to do their RND. You float the risk and if it works they implement it. Genius, really.

The latter seemed obvious to many people though. I think a lot of people ran with that risk anyway in hopes of becoming an acquisition.