A stupid question - somebody has to ask it so why not me :)

Why do you have to pay for an account to be created?

Can't a new account be free? And, to prevent abuse, there is something else as a barrier / safeguard. I don't know, activity, rewards, ...

I am asking this because I would very much like that the sign-up process is as hassle free as possible. If I have to pay with something I've never used, don't have access to and don't know how to get it ... then I'll turn away and forget about it.

Not a mass adoption friendly, I'm afraid.