One Link?
I too made the same mistake - signed up for the 2X/3X bonus, only to realize that I should have used the AMEX link since I am a cardholder.
If only the AMEX link were presented, could everyone still sign up or would non-AMEX holders be rejected? In my perfect world, we would all use the same link and those of us with qualifying cards would also score the bonus.
Just a thought.
-Goat