IHG has launched a Cyber Monday Deal that lets you earn up to 5x base points on hotel bookings. Since the standard earning rate is 10x, that means you can earn 50x base points in total. You must register for the promotion, book by Nov. 30, and complete your stay by Dec. 31.
This 5x multiplier applies only to the base points earned by IHG members, bringing the total to 50x. If you also have Platinum status, you get an additional 50% bonus on top of the base rate, which is another 5x. That brings your total return to 55x points per dollar spent. IHG points are worth about 0.5c/point to 0.7c/point, so this works out to roughly 50% off, which is a pretty substantial discount.