New York Times: Getting a Bead on ‘Buzz’:

“Marketing executives worry much more about word of mouth today than they did a couple of decades ago. But even companies that consciously do ‘buzz marketing’ do not necessarily know how buzz works. Word of mouth is hard to track or measure. After all, most conversations are private and ephemeral. Nobody keeps a record.

Unless, that is, the ‘conversation’ takes place in an Internet forum. To see how word of mouth might affect new TV shows, Professor Godes and Dina Mayzlin, a marketing professor at the Yale School of Management, tapped this recorded form of conversation. Using online archives, they tracked postings in Usenet discussion groups at the beginning of the 1999–2000 TV season. (The paper, now under review at the journal Marketing Science, is available at www.som.yale.edu/faculty/dm324/papers.asp.)”