Wikipedia
Twtbuck
Twtbuck is a performance based social media advertising and crowdsourcing platform which connects people with influence in Internet, especially social web, to big brands. It was founded by Gaurav Sharma in June, 2010 as an experiment during a job. It currently serves 416 advertisers, about 21,000 publishers and four agencies and ad networks
Twtbuck matches publishers with matching advertisers on the basis of geography and interest graph.