I also have a different question, I'm trying to sign up with Cathay Marco Polo, and they want $100 USD for signing up. Does that make sense to anyone?
Yes. There is a (hefty) fee for joining Marco Polo.
Asia Miles & Marco Polo are different but associated. If you sign up for MP you become a Asia Miles member.
Look on the Cathay forum stickys for more information.
http://www.flyertalk.com/forum/catha...polo-club-487/
And
http://www.flyertalk.com/forum/catha...hoose-why.html