The term first coined at a conference brainstorming session between O'Reilly Media and MediaLive International, which also spawned the Web 2.0 Conference.
A. Rivadeneira, D. Gruen, M. Muller, and D. Millen. CHI '07: Proceedings of the SIGCHI conference on Human factors in computing systems, page 995--998. New York, NY, USA, ACM Press, (2007)