Books by analysts at research firms have a tendency to be deadly dry, but not Groundwell by Forrester's Charlene Li and Josh Bernoff. That's the opinion of Ad Age's Abbey Klasssen who writes that the book is quickly building a following among marketing types. It's an opinion that appears to be shared by a lot of readers: the book, published by Harvard Business Press, debuted on Business Week's bestseller list on July 3.

Calling the 241-page book "one of the most comprehensive and useful primers on the sudden surge in social media," Ad Age'sKlassen writes that Groundswell "and its accompanying blog keep popping up in conversation among social-media experts."

One particular example she recommends for entrepreneurial marketers is the tale of Jason Korman, the founder of Stormhoek, a winery in South Africa. Korman grew sales to $10 million in 2007, up from $1 million in 2005—all through savvy use of social media. He says cultivated numerous mentions on blogs, gets wine drinkers to post images on Flickr, and maintains a presence on Facebook. "The Internet is Jason Korman's marketing department," the authors write.

What's your favorite example or anecdote taken from the book?