Viral marketing is a marketing phenomenon that facilitates and encourages people to pass along a marketing message voluntarily. Viral promotions can take the form of funny video clips, interactive Flash games, images, or even SMS text messages.

An increasing number of organisations are now looking for marketing strategies that rely on the distribution of viral video. This is because controversy, wit, and creativity, combined with the randomness of "word of mouth" distribution can cause huge amounts of people to distribute a video among their friends and colleagues. This in turn results in masses of random users being exposed to a video that promotes a brand.