Artpic Market is a market place where users can buy or sell their images, blogs and creative assets - Called CA henceforth. The images etc are listed in the market place and users can search for and find a particular set of images matching their keywords. For selling your creative assets the users must create an account with Artpic which is free. However, if they wish to sell their work they are required to subscribe for a license with a very nomial fee.
This registeration allows the user to do a lot of nice things with their CA's.