Here's how it works: you read a book you enjoy and you tell a friend. That friend tells another friend, the next friend tells the next, and so on and so forth, until the book becomes that year's word-of-mouth bestseller. That first recommendation gives birth to many. Simple. The concept of pass-it-on is not so new and not so revolutionary - think Tupperware parties - that is, until forward-thinking Web companies got hold of it and created their own, mightily efficient, money-spinning model known as the Viral Loop: the ability to grow a company exponentially because the customers themselves spread it. Super simple.Outfits such as Google, eBay, Flickr and Facebook all employ the model at the core of their business; all have seen their stock valuations skyrocket within years of forming. The genius lies in the model's reliance on replication: what's the point of using Facebook if none of your friends can see your profile, or using Flickr if you can't share your photos? Where's the joy in posting a video on YouTube if no one watches it? Thus, in creating a viral product that people want, need and desire, growth can, and will, take care of itself. Business has never been so straightforward, or so it would seem...In this ground-breaking work, the first to analyze this paradigm-busting phenomenon, we are introduced to the architects of the Viral Loop and the companies which profit from its mechanics. Insightful, timely and revelatory, it will reveal the secrets behind the most successful businesses in recent history, and will explain how the Loop will catch you up, sooner rather than later. Review One of the most astounding things about the Web age is how the best advertising is often no advertising at all. Penenberg masterfully explains how this works with case studies of products that were designed to spread. Every product can use a dose of this technique; this is the book to get to learn how. Recommended! (Chris Anderson, bestselling author of The Long Tail and Free)In tight, engaging prose, Adam captures the essence of the ever-scaling power of the virus. It's not just for geeks any more. (Seth Godin, author of Tribes)Penenberg has unlocked the secret to the most successful digital businesses. An indispensable read. (Robert Safian, Editor-in-Chief, Fast Company)Adam Penenberg's lively book opens a window to all of our futures. (Ken Auletta, author of Backstory)If you want to understand all things viral, this is the place to start. Penenberg's reporting gives us a ringside seat for some of the biggest viral success stories in history, from Tupperware to Ning. (Dan Heath, co-author of Made to Stick: Why Some Ideas Survive and Others Die)Penenberg discovers the perpetual motion machine for business and marketing... Buy this book. Catch a virus. Make a fortune. (Jeff Jarvis, author of What Would Google Do?)Instead of entrusting your business to a guru with an agenda and a ghostwriter, you should be turning to a pro journalist like Adam Penenberg, who understands the way media and money interact, has the critical faculty to engage with these phenomena in an unbiased fashion, and the technical facility to explain them to you in an entirely engaging, informative, and actionable way. (Douglas Rushkoff, author of Media Virus and Life Inc.)An intriguing expose of a simple idea worth its weight in gold and then some. (Cairns Post)Word of mouth is nothing new in terms of marketing a product... This is "the power of pass-it-on", according to Penenberg, who looks at how an old idea has been made new again by the likes of Facebook, MySpace and Hot or Not... Penenberg writes accessibly about this "paradigm-busting phenomenon" and makes it all sound so simple. (The Sunday Mail Brisbane, and The Sunday Telegraph)Viral Loop tidily presents a history of viral case studies from analog to digital...This history of social networking benefits from in-depth first-person research. (Cou