The key here is 1 free RESORT night.

SPG has been having some problems recently with very low occupancy at quite a few of their resorts so this is pretty good promo for them to offer especially with ski season and spring break are both over.

They arn't offering city hotels that have good occupancy. Starwood is just throwing out some free nights that would be empty anyway. Im sure the goal is hopefully some people use their free night(s) and buy a few nights onto that to make a complete vacation. Starwood has alot of mexico resorts and i know alot of them are having major problems filling aka both in puerto vallarta so this is a good decision for them. There is no way hyatt is going to reply with an all hotel FFN. This is a very targeted promo for reasons of filling resorts that need some help right now.