From Publishers Weekly

In this clear-eyed collection of case studies, Fast Company contributing writer and NYU journalism professor Penenberg examines the engine driving the growth of web 2.0 businesses like Flickr, YouTube and eBay to Facebook and Twitter: the viral loop. The concept behind a viral loop is simple-in order to use the product, you have to spread it, thus creating massive, user-driven growth cycles-after all, Penenberg explains, social networks like Facebook are wo (more…)