There's a limit on how much money you can send/recieve.
I uploaded $50 via moneypak onto my paypal, but it got limited so I couldn't send money to any user.
Well besides on Xbox.
When I created my account I had a few problems with this. I could not create an account without info at first and failed to find a valid source of info saying that it actually was possible. Now that people are saying it truly does work, I might want to look into it. I myself am PayPal verified as well.