A Sad Joke

I could not believe my ears today when the lady at the Toys'R'Us cash register seriously tried to sell me an extended warranty on two DVDs. Price of the DVDs: less than 30 CAD tax included. The offered warranty: 3 CAD. Does this mean that one out of ten products they sell is defective? Or simply that they are trying to improve their profit margin by 10% at my expense? This is the last time I shopped at Thieves'R'Us.