Good info for a new offer.

faults(from my perspective):

1) spending $750 in 4 months. Sure that's not to hard to do, but do I want to divert earning miles on other mileage earning cards to earn on this one?

2) spending $10,000 on the card in the first year. More difficult than #1, but not impossible. Still diverting spending from a 'primary earning card'.

3) spending $10,000 on the card in the second year. See #2.

If you want 40,000 AA miles from Citi, there's far easier ways. They love to give multiple cards and their CSRs push multiple cards.