Pay with Tweet is a free tool which lets you set up a social media campaign to promote your content on Facebook, Twitter or Google+ in a jiffy. It’s kind of social payment system where users get something in return for a tweet or post like. Make sure you provide users access to something exclusive so that they are motivated enough to take action. Reward or payment could be some e-book, some market research report, song, coupon, product or anything which could worth for a tweet or like.
Pay with a Tweet – An overview from Leif on Vimeo.
Pay with a Tweet also offers premium subscription if you are interested in advance stats and more than 2 campaigns running simultaneously.