Sharing a ride or renting a property is a high risk proposition and humans have traditionally relied on trust networks and connections like families and friends

Sharing a ride or renting a property is a high risk proposition and humans have traditionally relied on trust networks and connections like families and friends to find good customers and providers. I think the true innovation of the sharing economy is using technology to scale up these trust networks with rating and reviews to the level required by a modern city. These mechanisms have of course been known for a long time in the internet, but sharing economy realized its full value for renting and sharing rather recently.