Not necessarily. The iPhone, for example, probably had very few users prior to launching. (though the handful of users that it did have, such as Steve Jobs, probably provided a lot of critical feedback)
That's a valid point. Then again, the 3G iphone has push email and exchange support, which looks to be an improvement that came directly from user feedback.
There's got to be some sort of quality of user/user feedback/time launched algorithm in there someplace. :-)
I like this. It unifies big complex projects and light webapps. In the early days, Flickr was famous for iterating in minutes, based on feedback in their user forums.
Perhaps the real advantage webapp authors have is their ability to iterate. It certainly isn't anything else about the web platform!
The time equation comes from processing feedback loops, but the more users, the better the loops, the better the feedback, the better the product.
Given that, it seems to be that it takes 2-3 years to acquire enough users (and the resulting feedback) to make a good product.