SPG gold. I have 10 stays for the year, 8 of which were award stays with points earned via Crossover rewards. (Primarily an Hhonors customer.)
My offer was:
Nov.3-Jan 31, second stay = free night. Fourth stay = free night. Potential bonus = two free nights.
Also, I had to use Chrome for the link, as IE would not accept it. (Personally use chrome as primary, but here at work, IE is used.)