So far in this book, we have relied on a few basic items to create our site, and, as of right now, it is fully functioning. Users have the ability to log in, create to-dos, create buddies, and so on. And while these make for a good application, good applications will not generate revenue. The Web is filled with many bad applications, quite a few good ones, and far and few between excellent ones. In this and the following two chapters, we will try to add some excellence to our web application by applying some Web 2.0 techniques.