[alook]

Does this only apply to UI changes? Or can i fix, say, a logic bug as well?

Also, what kind of performance concerns might I see?

[mikestew]

You don't "fix" anything, unless by "fix" you mean "turn off broken feature". It's a nice idea, too bad they tout it with such deceptive marketing.

[nancyhua]

Hm, I hadn't thought it would be misleading and asked for feedback on the heading. I guess the people I asked for feedback already know how it works... Thanks for telling me this because we consider ourselves super straight-shooting and want to be clear. We'll improve.

[heardrwt]

I believe it works using their Visual Apptimizer, which means that it's only UI changes atm.

As for performance, i've seen no issues.

[nancyhua]

An example is hiding Facebook login. You can unhide it later (also without resubmitting) when you're ready to put it back.