E-tailing 2.0 in Second Life, Entropia Universe, and There.

E-commerce is poised for a fundamental change—a shift from making online purchases (commercial transactions involving a single consumer interacting with a two-dimensional Web page) to going shopping online (a social experience involving groups of people interacting with one another in a three-dimensional Web space). The difference between the two is as great as the difference between sitting on your couch leafing through a J. Crew catalog and heading off with friends for an afternoon trip to the mall.
Via: HBR Are You Ready for E-tailing 2.0? October 2006