oh, but we won't charge you until your 30 days is up, you can just cancel before then!*
*please forget please forget please let us charge you when you least expect it oh god please forget about us you fucking stupid forgetful dope
-- how I interpret "free trials" that work like this. You can terminate my service when my trial is up, you do not need my credit card information until I've actually agreed to purchase the service. There is literally no practical reason they can't just do that instead -- except, of course, that it makes them more money off of forgotten trial subscriptions.