are there any examples of marketplaces/services with similar implementations that have worked successfully? Elance does this (http://help.elance.com/forums/309

are there any examples of marketplaces/services with similar implementations that have worked successfully? Elance does this (http://help.elance.com/forums/30972/entries/34480 http://help.elance.com/forums/30972/entries/34480). They let you set milestones, so funds can be released gradually over time. Elance will mediate if there are any disputes (this will be your headache should you go this route). Alternatively, you can use an independent escrow service, such as escrow.com (https://www.escrow.com/solutions/escrow/process-service.asp https://www.escrow.com/solutions/escrow/process-service.asp). I'm not sure if this fits with your revenue model (were you going to take your percentage from the escrow account?) Definitely talk to a lawyer to see how liable you are when things go wrong.