I got the offer for weekend nights or Points, took the points. Slightly different then the OP
"Thank you for registering for this Starwood Preferred Guest(R)
promotion. Now you can earn 4,000, 12,000 or 20,000 bonus
Starpoints(R) when you stay four, eight or twelve times between
June 1 and August 31, 2007."
I'd like to understand the math there
4 stays = 4k
8 stays = 12k (2.5 times)
12 stays = 20k (>1.5 times)
Good math starwood.