Startup Idea : Peer to Peer Rental and Selling

A peer to peer rental and selling website for local areas. The website would be both a selling place for good and services, but would also allow you to rent out items that you already own. People can set their own prices for selling and renting, and timescales if they are renting. I have begun the development of this idea at letssharenow.com and am currently looking to promote within different geographic locations. Interested in ideas as to how to promote the use of this more extensively.