must be growing. I have actually seen a couple of ads on TV for the company. I haven't bought any tires from them, but many on this board have.
Michelin and Goodrich always seem to have discounts available at Costco, BJs, and Sam's Club.
As well, every time the mail is delivered there are plenty of flyers for sales going on at local tire places. So, I'd have to say I don't think there is a season for tires, unless tire sales spike before summer vacation driving, or beginning of winter for snow tires.
Any time I've needed tires, I have been able to find some on sale, somewhere.
Sam I Am