The social network effect of the web have been amplified by the emergence of the web 2.0 . Dedicated online platforms such as Facebook and Myspace now provide huge amounts of structured social network data to exploit.
Web 2.0 ... The Machine is Us/ing Us http://www.youtube.com/watch?v=6gmP4nk0EOE <ul><li>internet n↔n </li></ul><ul><li>classical web pages 1 ↔n </li></ul><ul><li>wiki, (µ)blog, forum, etc. n ↔n </li></ul>Ward Cunningham, 94 [Fabien gandon 2009]
why people contribute? I'm contributing? practical solutions social reward self-expression altruism Cook, S.: the revolution contribution: letting volunteers build your business. Harvard Business Review, Oct 2008.