I assume everyone knows about the 20% off weekend stays when using Amex? Might be targeted (I saw my offer via Amex Sync) but worth a shot.
https://hiltonhoteloffers.com/amex/
Terms
Offer is valid for select U.S. American Express® Card Members only and is exclusive to bookings made on the HiltonHotelOffers.com/Amex page. Fulfillment of the offer is the sole responsibility of the participating American Express Merchant. Offer valid for weekend stays booked between January 15, 2017 and March 15, 2017 for stays from January 19, 2017 to April 25, 2017 at participating properties in the Hilton Portfolio in North and South America, including the Caribbean. Offer is non-transferable. Offer not valid at Canopy by Hilton™ or Tru by Hilton™. Offer available for arrivals Thursday through Sunday, with a two consecutive night minimum length of stay requirement. Check-out from your stay must be on or before Tuesday, April 25, 2017 for stays through April 24, 2017. The reservation must be made within the booking period specified herein and individual hotel’s booking terms and cancellation policies apply. A limited number of rooms will be available for this offer. Discount of 20% off nightly rate relates to the hotel’s Best Available Rate, (“BAR”), which is a specific rate type that varies depending on time of purchase, is unrestricted, non-qualified and excludes discount rates. Rates do not include taxes, gratuities, incidental charges or resort fees (if applicable). Unless otherwise noted, all offer components expire at check-out and may not be used or applied for future stays. Blackout dates, early departure fees, and deposit and cancellation restrictions may apply and vary by hotel; please see individual property for details. Offer cannot be partially redeemed, has no cash value, and is not redeemable for cash. Advance reservations required and subject to availability. Not valid for existing reservations, previous stays or group bookings. This offer may not be combined with other select promotions, offer or discounts. Hilton HHonors™ membership, earning of Points & Miles™ when booking direct and redemption of Points are subject to HHonors terms and conditions.