An anonymous reader writes "This is a pretty good insight into some of the dangers of social networking and website customisation -- marketing and loss of privacy. When marketeers know who your friends are and what you are all into, it makes their advertising a lot more effective. From the article: "Why are the companies worth so much money? Why is MySpace worth over half a billion dollars without a proper revenue model? Why is Digg allegedly pitched at over $20m (at the last count) without any idea of where money is going to be pulled from? The answer is - data. Information. Marketing. Every detail about you and me. That is where the money is."