1Chapter 0 Viral Marketing: What Is It, and What Are the Components of Viral Success?

Firms are reallocating their marketing communication budgets to word-ofmouth (WoM) marketing. PQ Media (2007) reported that total U.S. marketing expenditures on WoM marketing climbed 35.9% in 2006, and similar growth is projected for the 2007-2011 period. This makes WoM marketing the fastest-growing marketing communication segment. Key drivers of the popularity of WoM marketing are the decreasing effectiveness of the traditional marketing communication tools and the developments on the Internet that enhance consumers’ abilities to exchange information.