The other day my fitness coach went online to pay a $250 deposit on her daughter's high school trip. She found the website and the correct trip, clicked the link to pay $250, and then faced a cell marked Amount. In a hurry, she typed 250, the amount of her payment, without thinking much about it.
Only when she finalized the transaction by clicking Pay did the total appear. My coach's credit card was charged $62,500. Yes, $62,500! And her credit card company immediately approved the charge.
What went wrong? When the coach saw Amount, even though she thought the blank was redundant, she typed 250. After all, that was the amount she needed to pay. But as a result, she paid $250 an extraordinary 250 times.
The word amount led the customer-coach in the wrong direction. Quantity would have helped her understand what the blank needed. How many (what quantity of) payments in the amount of $250 did she want to make? Just one.
Amount and quantity may be interchangeable in some references to money, for example: "The amount [quantity] of money we need to invest has increased."
However, I follow The Chicago Manual of Style's guidance on the word amount: "Amount is used with mass [not countable] nouns: a decrease in the amount of pollution; a small amount of money" (like the amount of her payment).
Following that advice, the website would not have used amount for the countable payments but rather quantity or number. It would not have caused my coach the hassle of canceling the $62,500 charge.
Have unexpected words on websites cost you time or money? Please share your story.