The .NET Demon team have just implemented an experiment that is quite a break from Red Gate's normal business model. Instead of the tool expiring after the trial period, it now continues to work, but with a new message that appears after the tool has saved you a certain amount of time.

The rationale is that a user that stops using .NET Demon because the trial expired isn't doing anyone any good. We'd much rather people continue using it forever, as long as everyone that finds it useful and can afford it still pays for it. Hopefully the message appearing is annoying enough to achieve that, but not for people to uninstall it. It's true that many companies have tried it before with mixed results, but we have a secret weapon.

The perfect nag message?

The neat thing for .NET Demon is that we can easily measure exactly how much time .NET Demon has saved you, in terms of unnecessary project builds that Visual Studio would have done. When you press F5, the message shows you the time saved, and then makes you wait a shorter time before starting your application. Confronted with the truth about how amazing .NET Demon is, who can do anything but buy it?

The real secret though, is that while you wait, .NET Demon gives you entertainment, in the form of a picture of a cute kitten. I've only had time to embed one kitten so far, but the eventual aim is for a random different kitten to appear each time. The psychological health benefits of a dose of kittens in the daily life of the developer are obvious. My only concern is that people will complain after paying for .NET Demon that the kittens are gone.