Just sent up a post about this with a screenshot of the offer and a link to register (not targeted). Amex is offering 4 extra MR points for a stay on a registered MR-eligible card at any Hilton where the bill is over $175, for a total of 5 MR points and the HH points you earn on the stay. Extra points on non-tax items (room rate, in-room dining, etc.) only. Good through 1/31.