Short answer: Many of them suck.
Today I took the bait when I saw an offer of a "free iPhone" on Facebook. Things got real ugly real fast.
I was instantly treated to a shitload of diverse and largely irrelevant offers on a web page. After checking the boxes, up popped another page with more offers -- followed by another page. Page after page, the offers kept coming.
Soon I started to check all of the "no" boxes in rapid fire. But no dice. I was ordered to check "yes" on at least one box on a page ... if I wanted to remain eligible to receive the iPhone.
Where I come from, we call this a bogus approach to lead generation. Anyone who checks that type of "yes" box isn't a lead, and any marketer that pays for that type of respondent isn't spending marketing dollars intelligently.
When a form reaches an oppressive length and a coveted carrot is involved, fatigue sets in and the percentage of "false positives" rises. Many people will say anything to stay in the game.
I'd like to give you a neat ending to this story, but I never made it to the finish line. I eventually swore under my breath and exited. Robert Rosenthal will not be getting a free iPhone.
Why would smart marketers put serious money into such an obviously stupid approach?