I just looked up what this "certificates" you all were talking about. Just ran a set of tires for my tundra. Discount tire wants and extra $45 per tire for a road hazard? lol.
This is baked into the $20/tire install at sams club.
Haven't looked at Sam's club but the Costco road hazard which is included is prorated based on the remaining tread. The certificates are not prorated, you get full refund for up to 3 years or 3/32" tread remaining. Whether that makes it worth it is up to you. Probably not.