This is very true, but I've also experienced this with credit card sign ups. People who really don't want to pay will sign up, and forget to cancel. Then they'll file charge backs and complain when they get charged. Requiring a credit card may eliminate not-serious buyers, but it makes the ones that actually get through even more of a pain to deal with.
You're right, but I'd be more concerned about ppl forgetting to cancel with a 30 day trial. A 14 day trial is short enough that it'll stay on users' minds.
