I did some A/B testing for a client a while back and the number of abandoned sign-ups was much higher with the CC option. With the non-CC option, the number of

I did some A/B testing for a client a while back and the number of abandoned sign-ups was much higher with the CC option. With the non-CC option, the number of bogus email addresses was also very high. I think your best option is to put a time-limit on the software and to block advanced functions.