Don't know if your "Discount Tire" is the same as "Discount Tire Direct" that I mail ordered a set of tires for my Subauru Legacy wagon from last year, but here is my story with that outfit:
Bought a set of Hankook tires from Discount Tire Direct last August, online, I think out of Arizona. Pricing was right, free shipping and included an $80 rebate from Hankook and a $75 rebate from Discount Tire Direct. The set of 4 tires was about $240 to my front door.
8 months and 11,000 miles later I am driving out of my neighborhood on a nice recently paved street and with the window down hear a "FOOP!" noise like when you run over a rock with the edge of the tire and it sends the rock flying. Get to where I'm going, have lunch and come out to find this. A freaking STICK in the sidewall of my tire!
So next day I call Discount Tire Direct and talk to the salesman about it. He finds my invoice, says you didn't purchase the $10 Road Hazard "Tire Certificates" for each of the 4 tires when you bought them......but here is what I'm going to do........I'm going to retroactively sell you 4 tire certificates for $40. Then I'm going to redeem one of those certificates to replace the tire that is destroyed. I'm going to then sell you another certificate for $10 for the NEW replacement tire I am going to have shipped to you at no charge.
So I says $50 gets me a new replacement tire to my door, and all 4 tires are now covered with the Road Hazard Warranty? He says yep, that's right. I said send it on. DTD took care of me, their prices are competitive with Tire Rack but the free shipping is the difference.