Great book, recommended by Facebooks Head of Growth (he gives this book to every new employee). If you are in the online business it's a must-read. Great overview how viral companies work. Loved the company stories and cases. ( )

How does trash like this get published? On page 12 he does not even know how to use the term negative feedback. In a book on feedback. Really, wtf. ( )

The internet has transformed how we communicate and it has given virality a whole new lease of life. In the past, word of mouth generated publicity for goods. Recommend a book to a friend and chances were that they might buy it too. However, with the advent of the internet, this effect has snowballed.

Virality is now an integral part of life, with events on the internet taking on a life of their own (recall how Obama's campaign used the internet and Twitter to groundbreaking effect). Penerberg has written a book which focuses on the viral effect used by sites such as hotornot.com and Facebook. In essence, what good is posting a video on YouTube if no one sees it. To grow, these sites have to get people to visit, connect and share. The author discusses the concept of the Viral Loop, or the point of referral which a website has to pass in order to become self-sustaining (i.e. have a viral coefficient greater than 1.0).

While the book claims to reveal the "Power of pass it on", it really is more a history of the most successful websites in recent years. It takes us through Ning, Hotornot, Facebook, Flickr and many more, but doesn't really reveal too much other than a potted series of anecdotes. Ultimately, while interesting, it's not very revealing. ( )