I understand y people might be annoyed with it.. but the point is we were trying this trick and if we actually were scammers i would continue doing that and generating traffic.
It depends on number of factors one being number of followers that particular user has on Pinterest. An average user having 100 followers could make something between 1$ to 3$ per post.
We are currently on Pinterest only so as to ride the Pinterest growth tide. However we will soon integrate Twitter, Tumblr and Youtube. We plan to be the one-stop solution for social media advertising.