Web Service Pricing Models

One of the blogs that I read religiously is Joel Spolsky's Joel on Software.  His company makes a product called Copilot that "lets you remote control someone's computer over the Internet to help them with technical problems".  This is a perfect tool for people like me who help family members (the type that think that the best use of email is to re-mail jokes) help troubleshoot their computers. Today I read about a new pricing model for it: they're making it free on weekends.  That's the kind of thing that you can do with services and combined with a simple client-side software download, the solution is a great example of a software+services offering.  I'd love to hear some stories of how people have used it or similar tools.