Kmart is simply trying to get you to spend money in their stores. They already know they are going to take a loss on out of season candy, so why not make y'all come back within 14 days? I've started to slow down my spending at SYW, they keep sending me $10 back in points coupons, but the threshold gets bigger and bigger. That's how they get you hooked.
I have noticed an intresting trend however, if your getting lousy SP offers or coupons, try letting them expire or simply don't load them to your account. This seems to trigger something in their system, and you probably will get a better offer next time. (Eg, I let a $4 off $35 and a $7 off $70 expire without even clicking on the email, yesterday I got an $8.00 off $30 and a $10 back on $20 coupon)
SYW is a great rewards program, but you gotta play the game so to speak.
Just my thoughts, I know some of you veteran SYWers probably know this already.