<i>As the days go by, more and more people come onto the service, and see an ad-free environment. Introducing that sometime in the future is going to be a bitter pill to swallow for a lot of users.</i><p>Throughout his whole essay he keeps asserting that advertising will drive users away but I don't think that's necessarily the case. I'm sure a lot of casual Internet users don't care about an ad here and there. And then there's always ways to filter the ads out (think Adblock).