I deleted my Twitter account when I drew the analogy of: imagine a magazine, that your friends can subscribe to, to read your thoughts. By contributing to this magazine you contribute to your friend's desire to "buy copies" of it, and you contribute to its ability to sell ads. I decided I didn't want to do that any more.
Maybe it's the same with the Guardian. Although when I left, Elmo hadn't bought it and it actually had legitimate businesses buying ad space.