I would say 37signals and FogCreek/Joel On Software.

I was thinking about the same thing when reading the comments on TechCrunch: there is a big following that would buy it in big part because it's from TechCrunch. Or let's say that, in all these cases, the blogs are used as a great advertising platform.

You can't blame them, building a following is hard work too.

Ah thanks. I was in the mindset of a hardware product.

Any blogger who has published a book of their "best" blog entries.

Not exactly in the tech product area, but Wil Wheaton has spun his relative fame from Star Trek into a widely read blog, and then a couple of books, and speaking appearances, and other writing for the LA Times, Suicide Girls, various comic books, etc.

Through is blog/twitter he's managed to associate himself with all things "geek" and found an audience who will buy his work.

many webcomics make money off t-shirts, books, etc etc with a similar model.