[malandrew]

Based one what time you typically leave the house and where you go everyday, I'm certain there's also room to mature this market by suggesting carpooling groups to anyone who has tried to use the service at least once:

For all users who try UberPool at least once, find clusters where they all leave regularly at approximately the same time and head to the same destination.

Uber can even ask something like "Do you mind if we collect your commuting data for 1 week. If there is low variability, find clusters and suggest routes.

It think this could work bananas in places like SF-SouthBay, SouthBay-SF, and Washington DC where a sizeable chunk of people move back and forth in the same direction each day.