200 You Have a Book in You your selling for you. You can inspire electronic word- of- mouth advertising that will be much more e昀昀ective than any selling you could do on your own. Give Maximum Attention to Key Sites Nothing is more amazing about the Internet than how fast things change. In less than a year, YouTube went from nothing to hundreds of millions of users. MyS- pace opened up the whole new universe of social net- working, though today it has fallen far behind Facebook (with over 2.45 billion users) and YouTube (with 1 billion views per day). 吀栀e Internet is constantly changing; by the time you read this, it will undoubtedly have changed again. But for the foreseeable future, the key social networking sites are Facebook, YouTube, LinkedIn, and Twitter. 吀栀ose are the sites we’ll be looking at in detail. Even if others supplant them in the very near future, the principles you’ll learn by studying them are likely to become even more important. Facebook: 2.45 Billion Users! Facebook’s business model is based on building traf- 昀椀c. Plain and simple, it’s about getting as many users as possible. It’s a party, not a trade show. Toward that end, Facebook is designed to prevent people from turn-