I used to run AdWords regularly. I knew I'd be onto something when I almost broke even. Sometimes I'd be in the hole a bit and that was fine. If I broke even on first attempt, I knew I had a winner. This was affiliate marketing btw. Once I broke even, it was a matter of tweaking, refining, testing and more refining until you're in the green.

That being said, I think it's obvious that I totally disagree with the author. You should run ads. Absolutely. If you get a paid customer right away, that in itself is a much stronger indicator than someone signing up for a freemium product. I find this article carefully crafted to to be somewhat controversial, perhaps on purpose so it reaches the front page of HN. Mission accomplished. Congrats!