In other words, you can think of a city as a technology for lowering the costs of face-to-face interaction in precisely the same way that the Internet is a technology for lowering the cost of exchanging information.

FORBES: Disruptive Blogging

Tall buildings, walkable neighborhoods, and a good transit system reduce the average cost of face-to-face interaction in exactly the same way that steam ships and low tariffs reduced the average costs of shipping goods to the other side of the world.

FORBES: Density Limits Are Urban Protectionism