Ben is right: If you have existing niche traffic you can test out cams there and see how it goes. But I should warn you that many times it doesn't work, esp. if you're running a "free" TGP - it's a BIG stretch for these guys as cams are very expensive vs. pay sites.
However, as for conversions, I'll repeat what I've said many times before: Conversion rate is NOT the stat to be focusing on. Earnings-Per-Click is really all that matters. (Aka: How much money do I make for every visitor I send my sponsor?). With cams you can get numbers that pay sites could never hope to match.
Consider a webcam sponsor paying 20% revshare. Guy makes a $20 deposit, you get $4 .. not impressive, but that's the minimum. Customers can (and often do) make several $100 deposits in the same day - $20 a pop. Medium fish can drop $500 - $1000 / month, and aren't that rare. Whales can drop $5k/month and much more (I've personally seen $15k in one month).
Now if you have any kind of decent traffic, do the math with even a poor conversion rate ... pay sites can't even come close.
