I just stayed 8 nights in an Executive Apartment figuring this would take me over 50 nights for the year. On checking my account, I noticed I fell short but couldn't find anything on the Marriott web site to explain it. This is a lesson learned for me....I should have looked in FlyerTalk first as it would have been so easy to check out and move to another Marriott where a "night" really means "1 night".