Nitpick: There were such marketplaces before so it's not really fair to say airbnb made them. It is the one that's really 'gone mainstream'. There were likely a

Nitpick: There were such marketplaces before so it's not really fair to say airbnb made them. It is the one that's really 'gone mainstream'. There were likely auction sites before eBay, sync products before Dropbox and music players before the iPod.