Mobile Product Marketing Question:

This to me is the heart of product management. You may have said a lot of great things, but if you don't have a great answer to this question, we are done. There are lots of good answers. But I'm looking for a mix of things. First and foremost, have you put thought into this. If you just ramble off an unrelated list of things, we are done. Second, I want to understand how you balance all the competing inputs: user feedback, business needs, the CEO's pet feature, engineering favorites, time to build, cost, market needs, and so on.

This is a great question for gauging how well someone understands the business context in which they work and the market in which their product sits. It's also a good measure of critical thinking. If you want to move on to an in-person interview, you better nail this one.