Try before you buy is a good way to win over a user. I've looked to try a heap of services lately on the Internet but they all want my credit card details to sign me up straight away after the trial period ends. Consequently I don't sign up for the trial and hence I never sign up for their service. I created an Internet site running in a similar fashion once. Many people made it part way through the process but then balked when they realised they needed to enter credit card details. I don't blame them.