This sounds like a great business model actually: release a killer software product, and make the beta free to get users addicted, with the caveat that when you get out of beta, there will be a "small" monthly fee. Then, when it's time to go mainstream, charge them $100/month to keep access to their data. And make sure there's no way to go back by locking the users' data behind encryption for "safety from hackers" or similar.