Just know that I won't be using your product. And most of my friends have no credit card either.

Besides not being able to sign up, I also wouldn't want to. From what I heard about how credit cards work (as opposed to debit cards, which I think is the right term for the cards that we commonly use here), I'd never sign up for a free trial and give the developer (and any potential hackers) the permission to withdraw arbitrary amounts from my credit card. I sign up for so many things and try out so many demos, it'd be a major security risk. I even prefer not to give out my real name anywhere, let alone bank account details.

But then again, if you think this system works for you, go ahead and use it. If it makes you richer, who am I to say you shouldn't.