I signed up for 2500 as a trial I will post my results. Its got to be worth $3 though I figure I dont need many clicks to double my investment but only time will tell.
Update
So far I am about 10% through my 2500 and so far no results but the thing is if I follow some of the referral URLs they have nothing at all to do with the niche of my site. I thought this was going to be targeted traffic!