Basically, here is the deal. The site will allow users to submit an entry to a contest that will giveaway something like a game, software, electronics, etc. The giveaway is actually real...so no blackhat involved. What I want though is for visitors to fill out a survey before they can enter the contest by using a basic content locker on the entry page. I am unsure of what CPA networks that are reputable would allow this so any help would be appreciated. I don't want to waste my time or the CPA's time if I can avoid that!