I thought we were only limited to 5 questions a day. I've noticed some pretty bizarre questions though. I reported one because it was, in my opinion, obscene. I've seen several that bordered on it, and some that were just out-right stupid. I'd like to report them, but I wasn't sure either.
Update: I just found this in the Help section:
The Q&A feature allows you to ask other Hubbers to answer a question for you in the form of a Hub or brief comment. You can request a specific Hubber to field your question. When a Hubber has answered your question, you can receive an email notifying you.
•When is a good time to visit Vietnam and why?
•Where’s the best place to buy a used guitar?
So, I am assuming that if it is promotional that we can report it.