They're not handling the financing. It appears to be going through Citizens Bank, and is an installment loan. [1]
And, if you were hoping to use someone cheap like Cricket instead of Verizon, no such luck there either:
"1. The iPhone Upgrade Program is available to qualified customers only with a valid U.S. personal credit card. Requires a 24-month installment loan with Citizens Bank, N.A. and iPhone activation with a national carrier — AT&T, Sprint, T-Mobile, or Verizon. "
And, if you were hoping to use someone cheap like Cricket instead of Verizon, no such luck there either:
"1. The iPhone Upgrade Program is available to qualified customers only with a valid U.S. personal credit card. Requires a 24-month installment loan with Citizens Bank, N.A. and iPhone activation with a national carrier — AT&T, Sprint, T-Mobile, or Verizon. "
[1] http://www.apple.com/shop/iphone/iphone-upgrade-program