This Is A Bad Sign, Part 2

(We have signs all over the store advertising 30% off hardcover books in huge letters. A customer approaches, holding a paperback.)

Customer: “So, this is 30% off?”

Me: “No, sorry it’s only the hardcovers that are on sale, as the sign says.”

Customer: “Well, that’s very misleading.”

Me: “Sorry? Why is that sign misleading?”

Customer: “Well, it’s misleading because I didn’t read the sign properly.”