mason and phil are correct. Incentivizing traffic means that you are offering your surfer some sort of benefit (cash, prize, points, gift, etc.) for clicking through and/or completing an offer.
The lure of answering a question is not an incentive.
However, if you are saying "Vote YES/NO do you like beer. Vote now for your chance at an iPod". Then you are incentivizing, even if you are not personally giving the chance for the iPod.
Of course, there is an exception. If the zip submit does not allow incentives, but you are using their approved creatives which say something like "Vote YES/NO do you like beer. Vote now for your chance at an iPod", then that would not technically be incentivizing as you are simply using what's provided.
Your best bet is to show your site to one of your AM's who will be able to let you know for sure.
