Awesome, I think if that was a little more "idiot friendly" on the site page you'll see a higher conversion rate on that signup form.

Credit card barriers on free trials is effective at 'keeping out time wasters' but you also keep out genuinely interested potential customers. It's a fine line.

We were exploring a similar discussion at Virally over this last week, and we've decided to not ask for the credit card on our free trial signups. If they haven't entered one before the end of the trial, their account downgrades to our free-forever account.