Having played with and thought about the costs associated with handling transactions and paying people (and we’re talking monetary|infrastructural costs, not social|spiritual, thats a different post), I’m always struck by how much overhead there is; overhead in fact swamping the value of many types of transaction.
Which is how I know I’m living in 21st century when I was able to buy David Brin’s latest work, with money I made filling in phone number information on a couple SF restaurant listing, and have enough left over to cover backing up the contents of my virtual server I just flashed.
No real insight but having just lived through it, it felt worth noting.