If u do the browsing lately on the net, u will find many site or blog is charging their visitor for wht they called "Doing Survey first then content" tactic, for instant, I'm going to free to watch movies site, in order to watch the free movies, I have to do the survey or questionairre, submitting your cell phone number to them, then u can watch the content. So wht u think, this tactic is generating money? or working? as I can say its pretty annoying to the web surfer, the ironic is the site is on top 10 of google search.
it doesn't hurt traffic as much as you think thats why those sites are still in the top 10. if your going to join a content widget network join through cashbackaffiliates.com so you get some extra money ^^
Absolutely, surveys before getting to the content will make you more money than any kind of advertising on the page. The best network for that would be leadbolt. I can tell you from experience that is definitely the best way to go.