Registration is required and available from December 16, 2010 through March 31, 2011. Various targeted offers reported: · 2 stays = 1 free night for a category 1 to 4 hotel. Limit of two free nights earned during the promotion. (This seems to be most common) · 20 nights = 35,000 points; 25 nights earns additional 15,000 for 50,000 points total. · 15 nights = 25,000 points; 20 nights earns additional 15,000 for 40,000 points total. The primary offer is one free night after every two stays with an earning limit of two free nights during the promotion period. Free nights are restricted to Marriott Rewards category 1 to 4 hotels. Marriott Rewards has 8 hotel reward categories. The vast majority of Marriott hotels are in categories 1 to 4 with over 2,500 hotels around the world in these four lowest categories . The major drawback of the free nights promotion is many major cities like San Francisco start at the category 5 level for any downtown hotels. New York takes a category 6 reward for any Manhattan property. There are plenty of properties, particularly major airports, where you can redeem a category 4 hotel night, however, you may find your options limited to the suburbs if you are planning free nights restricted to a category 4 hotel reward for a major city trip. MegaMiles Marriott also has a Triple miles MegaMiles promotion running during the same time frame. You must set your Marriott Rewards account earning preference to miles to view and register for MegaMiles.