You also need to look at when basecamp & campfire were first released. They were significantly better in comparison to the competition at the time. And while basecamp doesn't personally fit with how I run and manage projects, I know a lot of people who are very happy with it. It fits in with how a lot of companies (many of them not "technical" companies) run their projects. For a certain kind of business it's a very good product.

"Nothing wrong with that, but it's good to be clear about the distinction between a company that makes great product and a company that's good at marketing itself"

A company that's not good at marketing and sales doesn't stay a company - no matter how good the products are ;-)