I didn't mean to convey any moral judgment at all, not say that you should care about some company's bottom line. I'm just trying to say Darn Tough knows you can't truly expect a pair of socks to last your lifetime - and we shouldn't either.

The company plans to replace a certain proportion and that a larger proportion of buyers will never exercise the guarantee - not because they'd be wrong to do so but because many folks simply won't, for whatever reason. The fact that a larger proportion will not exercise their guarantee may well be what makes it economically viable for the company to offer the option.

Edit: To be clear, I'm not the commenter who called exercising the guarantee "overreach". Please direct your indignation that way.

Yeah, I think people are missing the point on these lifetime guarantees.

Nobody is truly expecting socks to last forever. Darn Tough knows fully well that their socks won't last a literal lifetime but the value the guarantee adds to the brand boosts their bottom line more than the small proportion of buyers who will ever ask for replacements.

It's akin to why gift cards are such a boon for retailers; a pretty significant portion of them will never be redeemed, meaning 100% profit for the store.