Poll: Why are you building a web app? (Research for my book)

Fellow HN'ers! I'm currently finishing up a book on web apps (http://fivesimplesteps.com/books/designing-web-app-success), and would very much like to start it off with a little introduction about the varied reasons why people create apps. If you'd be so kind, please help me out with the poll below - thanks so much!<p>Why are you building a web app? (The primary reason)