they are all scam. i have been clicking ads for 3 months and when i reached the free minimum payout, they wont release your money. they will let you pay for the membership fee. one friend pay 39$ for the membership fee but they never got any payment nor response from the site.

here are a list of bullshit ptr sites:

www.promails.org
www.1centEmails.com
www.2-dollar-mail.com