Forrester Research's concept of Social Technographics classifies people according to how they use social technologies. The approach is already a few years old, but Forrester now updated their profile tool with research data from 2009...
I am not sure how valid the actual numbers are. But it is probably a good way to compare countries, age groups etc.
About this Site
This is the personal website of Björn Ognibeni - Trusted Digital Advisor / Practical Visionary, living in Hamburg, Germany.