Marketers love to chase word of mouth — but not enough have learned how to harness its potential. The good news: word-of-mouth platforms (WOMPs) stand ready to help marketers identify the right advocates or influencers, activate those advocates or influencers to action, and then measure the results. The bad news: the vendor landscape is cluttered and confusing. In an effort to make marketers' decisions easier, this report lists, organizes, and describes the dozens of word-of-mouth platforms from which they can choose.