This is actually the first time I had an offer from this site. You would be asked for a review or just a mention on their product or site then you will be paid. I guess, this has something to do with my site's Alexa ranking. Since I actively updating my blog, my Alexa ranking is improving from 6,000,000 to 1,000,000 to 400,000. Adgitize is also a big help giving me 50+ unique visitors everyday.
Visit SocialSpark site. I just signed up and after few weeks, I had an offer.