A few months ago, I found myself in need of some new tires. Like most people, I bought two tires, and kept two of the older ones on my car.
At the Sam's Club tire center, the guy working there told me that they have to put the new tires on the back (of my front wheel drive car). He cited some sort of statistical research that says that cars which have the rear tires changed have fewer accidents. I acquiesced, but in my mind I was thinking: "Whud 'ju talkin' bout tire man?" (Ala Diff'rent Strokes' Arnold Jackson.)
I know why people who replace their back tires first get into fewer accidents: Keeping the old tires in front causes the car to have less traction, thus the driver is compelled to change the front tires as soon as possible.
I suppose the tire guy won (sort of)... I caved, and bought two more new tires last night. I did buy them from a different store however. I am currently enjoying the good traction that I should have had months ago. I wonder whether that stupid policy (about changing less-necessary tires first) is chain-wide.