People buy virtual goods usually for one of three reasons: to express themselves—so they’re buying virtual goods to make their avatar look terrific—or to build relationships with other people in the form of gifts. And [the] third reason, especially in gaming environments, is that virtual goods enhance your power to effect change, to win, to do what you would like to do in that area.

Cary Rosenzweig

Vía | eMarketer

Y la gente compra muchos productos virtuales, además. Parece una locura, pero estamos hablando de un volúmen de cinco mil millones de USD en 2009, según este artículo publicado por Catalina Franco en Tendencias21 (¡gracias @nordez!).