Does the SaaS model really work?  Really?
jedc: If it helps, I tried modelling 37signals' revenue a while back.  Based on some of their posts and a few guesses I think they've got about 10k paying Basecamp customers, and across all their products will have about $8million in turnover this year.My original blog post is here:
http://blog.jedchristiansen.com/2008/02/25/37signals-is-one-...You can play around with the spreadsheet I created, though I hope to update it soon.I think it's absolutely easy to see that you can get 5000 users paying $20/month if you provide $20/month of value to your customers!  Are you saving them that much per month in other costs, or generating new revenue through your software?