How to make money from Scratchback?

I found this website while i was Surfing, Scratchback.com is a Website which allows your readers to give tips or Suggestions to increase your blogs performance , Every time a user gives a Tip U earn money from it , Its up to the Blogger (Blog owner) to decide the cost for the Tip to be Displayed on his Blog or website. In Return the Reader(Advertisers) gets to keep a Link or Image on your Blog.I think this is a good Procedure as it gives something to both the Blogger and the Reader(Tippers) to be Happy About