It looks like our iPad can access the Marriott's iBAHN network for free ... their system can't redirect to the hotel landing page so it gives it free access. Tried my MacBook and it redirects/won't let me do anything else.
I was just staying in a Marriot two days ago, but on the iPad it redirected me right from the settings menu. The front desk just gave me the code lol. I'm staying in a Hampton now and the wifi sucks...