Good point, many of these sites are still underdeveloped, while some like http://Zilok.com are operating successfully. I think that the aim with ShareFair was to be local and build a sense of community. Maybe we can discuss ways of differentiating ShareFair operations in addition to utilizing existing sites.
Maybe ShareFair could host collaboration hours in a community center to give people ideas, know-how, education, etc. One issue with the existing sites is that there is not always very much available for renting in a particular zip code mainly due to interest. If ShareFair could be launched around specific communities and encourage every member to participate and collaborate, traffic within a community could be specifically increased.
1) Building on Elmar's proposed idea of creating a ratings system, users can build their credentials and earn various titles until they reach coveted "power renter" or "power lender" titles.
2) People wishing to lend would have to specify an "equipment value," and give ShareFair a percentage of the rental fee (we can call this a deal fee). People wishing to rent would have to post security deposits (which would be a percentage fraction of the "equipment value") held by ShareFair. A required security deposit would require lenders to rent to any user since it is backed by ShareFair. This model would encourage users to interact.
2) ShareFair could implement a special pricing scheme to establish users and build ratings. New renters would have to pay double rental fees and post 100% security deposits until they reach (5) favorable ratings. First time lenders would have to give ShareFair a high percentage of the rental fee (deal fee). As users earn various trust rankings (or titles), rentals fees, security deposits, and deal fees would be reduced.
I think these ideas would encourage users to participate in this system and incentivize good behavior/proper usage. Nice concept Elmar!