The author has not charged money for his app yet so while we know some users like the application, it doesn't tell if they are willing to pay for it.

But my real point is that it depends on the type of users you have. I sell my web apps to towns and city administrations and also to some small businesses. At first we had a few clients for free, their employees didn't use the application much and we did get some feedback but not that much. The year after, we found clients (including one from our original free clients) who were willing to pay for the service (incomplete, buggy and all) and things changed a lot. These clients had much more users day to day using the system, they also provided much more frequent feedback.

If your client is an organization, the importance something has for them is very often tied to how much of their budget they dedicated to that something.