Depends, credit card or not credit card? theres one on adult alchemy that pays $30 per USA free member, cc required tho. webcams.com pays $25 per free member (free member gets $10 to spend on webcams), cc required. I dont know of any adult sites that pay more than $5 per free sign up without cc. But if u dont mind getting people to whip out credit cards, then give the top two a whirl.