Aah the great "good engineers don't need marketers" debate. I guess the only point I can really make is, what if you had someone proactively reaching out to others that didn't write about you, but would have if they'd heard about it, since SproutRobot is so awesome? By your train of logic, then, you could've gotten 100x the return on a marketer's efforts, and their job would've been an easy one because they wouldn't have to do any convincing.