Should a cafe be used for trading?

Image via CrunchBase, source unknownTo my purist way of thinking a cafe's primary purpose is all about building community. It is a place for chit chat. It is not a place to buy and sell items. To do that you need a specialist service, perhaps an Ebay or other auction site. Or you need to set up a special group that has special rules and moderators focused on managing the sales process.

But that is not a cafe. Of course this could just be my prejudices and cultural asiprations speaking but that's what I think a cafe is about.