Epic,
Wegcash and
ARS pay on free signups....though the surfer has to supply CC info for you to get paid. payouts range but are typically around $25 pps.
for
Pussycash, the surfer has to buy a certain $ amount of time before you get paid on their free signups. i forget how much exactly.
at Lars right now, you can get paid $25 for a $1 signup...or 20% revshare....or get $70 pps via their cams.com sites...but the surfer has to buy $20 of time for you to get the $70.
in my own experience, I have 21 free signups at Lars over the past 3 months and they have made me $45.75 total....however, these all came from surfers i sent to the $1 signup sites...they didn't sign up there but eventually made it over to one of their free signups sites via a console and signed up. on the $1 sites at Lars, i've done around 1:280 or so since last november.
at this point, i haven't sent enough traffic to each to tell you who is the best, especially since Lars has had some great promotions recently...and Epic can pay a lot if you can send a lot of signups.