I received two emails -- one for 3x on summer entertainment (movies, amusement parks, aquarium/zoo and arena/stadium events) up to 2,500 miles,
and the Amazon 10x/Back-to-school 3x.
I did the entertainment offer first, but even though there are different invitation numbers, when I tried to register for the Amazon/Back-to-school offer it said I'm already registered.
So I don't know if it's either one or the other or if I'm registered for both.