I tried it, but you can't sign up more than two times with the same creditcard. Ip didn't matter (tried through tor/proxy as well).
Oh, and you need to verify your account with a text message, and they will call you to ask whether you need assistance
And what message do you see with the third time?
Got something like "This payment method is not available at the moment".
That's the same message I got while trying to setup a 3rd account. And shortly after that the first 2 accounts free trials were canceled and they said, "You have already used your free trial or are ineligible"