That reminds me of a brand of work socks Sears used to sell. They also had a lifetime guarantee. The socks would last about a year but the guarantee was good. They came in 3-packs. When I bought a pack, I'd stick the receipt to the label and toss it in a box. When I had 3 worn out pairs, I'd get out the oldest receipt and send them in. They'd replace them without question. I went for many years without buying socks. The problem was that the replacements never came with receipts and you HAD to send in the receipt, lifetime or not, so you couldn't get the warranty on them.
