LensCrafters will let you exchange a pair of glasses. For any reason — even if you just changed your mind. They’ll re-make a pair of glasses again and again. Until you’re happy.
Sears will let you return appliances, even after they’ve been installed. They’ll even deliver new ones, for free.
This may cost the company hundreds of dollars for a picky customer.
But that customer will be back, again and again.
The cost of a replacement is less than the profit when you earn a customer for life.
The cost of a replacement is less than the sales gained from the word of mouth of a wowed customer talking to friends.