The Unexpected Bonus is similar to the Mega Bonus that Marriott runs a couple of times per year. They try to customize these offers for a reason no one can figure out. If you earn points, there appears to be two possible offers..1) Stay "X" amount of nights and receive "x" amount of points. 2) Stay two times and get a free night certificate for a category 4 or 5 hotel. maximum of 2 or 3 nights. As boldie recommends above...if you don't see something in the "Promotion Central" section on the marriott.com site...give customer service a call.