1. A marketing strategy in which various unconventional techniques are used to generate word-of-mouth excitement about a product. Conventional media outlets may be deliberately avoided in order to create an air of mystery or exclusivity.
2. More specifically, a form of direct marketing in which a company encourages Internet users to forward its material in e-mails, usually by including jokes, games, or other entertaining features. The aim is that publicity for the company will spread in the manner of a computer virus.