I'm merely hypothesising. Here's another one: 5) Facebook's terms and conditions have adverse effects on Zynga, enough to turn them away from the platform. Z

I'm merely hypothesising. Here's another one: 5) Facebook's terms and conditions have adverse effects on Zynga, enough to turn them away from the platform. Zynga is only going to stick around if there's money to be made. If there's 1 billion users but only marginal profit to be harvested, Facebook's lock-in and reach means squat to Zynga. It's entirely possible that Facebook's terms and conditions will evolve to somehow disrupt Zynga's revenue stream (e.g. no forms of game currency other than Facebook credits). There's so many ways it could happen it would be prudent for Zynga to have a plan B at the ready. I'm sure they have one.