It’s a form of locking in customers. If I get a flat that I can’t plug myself, I don’t necessarily want to have to go back to any particular tire chain and argue over whether the tire is 55% worn or 45% worn.

We once got the tire policy included at no cost during a promotion. Got a flat that I couldn’t plug. I measured the tread with my treadwear gauge and unsurprisingly, their measurements came up short. When I pulled out my gauge and insisted we go out to check them, low and behold it turns out the tech had “made an honest mistake”.