More than once Hilton Honors ran a 5/10/15/20 promo. First stay 5K bonus points, then 10K then 15K then 20K - so four stays netted 50K extra points.

This was also at the time where you could get a six-night stay at a Hawaii resort (Oahu or Waikoloa) for 100K points all in. We scored this one twice back in the day!