Hi

I think about to pay for each Ad a amount of money to a user to posting Ad
like if a user post a new Ad he will reward with amount of a point like 10 or 100 points for each Ad
and when he reach a amount of a point like say 10000 points he will get 1 or 10 dollars for posting Ad on the website

is there any pluging like this or is it posible to make a plugin like this?

thanks