social networking sites do not deepen friendships

This article in the Guardian notes:

Social networking sites like Facebook and MySpace do not help you make more genuine close friends, according to a survey by researchers who studied how the websites are changing the nature of friendship networks.
Although social networking on the internet helps people to collect hundreds or even thousands of acquaintances, the researchers believe that face to face contact is nearly always necessary to form truly close friendships.

Duh.