At its core, word-of-mouth marketing is all about marketers recognizing the power of a conversation and seeking to participate in it—by activating it, organizing it, listening to it, and measuring its impact.

Word of mouth (WOM) is the sharing of an honest opinion between two or more people. Although there are a number of different techniques under the umbrella of WOM, they all share these fundamental attributes:

• Two-way communication: WOM is about marketing with consumers, not simply broadcasting scripted messages at them.
  
  
• Facilitating communication: helping consumers to share their honest opinions and providing tools and encouragement

We have all heard repeatedly that traditional media is losing its impact as a result of a variety of trends, including declining viewership and disruptive technologies such as TiVo, Podcasting, and video on demand. Simply, it is becoming more difficult than ever to connect with customers, during a time in which such connections are essential. Customers have more choice, voice, and control and more ways to create, communicate, and collaborate than ever before. So, amidst this sea change of consumer behavior and media consumption habits, marketers are increasingly looking to what may be the oldest, and arguably the most effective, form of marketing there is—WOM.

Although we've all experienced its power first-hand, the rise in interest in word-of-mouth marketing has led to a body of research that has shown what many have long believed: WOM is the most effective medium to drive sales. In their simultaneous media usage study in 2005, BIGResearch reports that WOM ranks highest in driving consumers' purchase decisions—above TV, Internet, print, and radio.

Just how widespread is WOM? According to the Keller Fay Group, Americans engage in 3.5 billion brand-related conversations every day. We love to talk about products and brands. And although the vast majority of those conversations still occur offline (92% says the Keller Fay Group), new online tools and technologies are giving people more and more ways to stay connected and to share their opinions.