Disclosure. Disclosure. Disclosure.
No one in their right mind would even consider this model. If anything, the cancellation window should be a bit longer, rather that shorter than what the terms and conditions state.
3 days means 3 days. 30 minutes means 30 minutes. Decpetive practices means you may find yourself out of business and with less freedom than you've ever had, or at least a lot less wealthy than you've been before should you find your self in front of a judge.
--Rand