I had an interview with FB last year for a Sr. Data Scientist role. The technical interview asked the following question (paraphrasing):

Tweens and teens view FB as a platform for their parents. How can we test this statement? And if this statement is true, how do we grow into this market and test that they are engaging with the platform?

I thought the question was odd thinking they could have provided a better hypothetical than focusing on getting more teens to use FB. Then I remembered why I don't have a FB account and deemed this probably wasn't hypothetical. I then told myself no paycheck is worth working on such problems.

Seems I wasn't far off in my assumptions.