Why Gasoline Is Priced With Nine Tenths of a Cent?

Why is gasoline always priced with nine tenths of a cent? No other products are sold that way. —Bob E. Peel, Stratford, Conn.

A shirt that's $9.99 feels a lot cheaper than $10, doesn't it? Just like that, gas marked $1.36 9/10 strikes most drivers as a bargain compared with $1.37 per gallon—even though gas stations just round up. (Because you can buy fractions of a gallon of gas, they can charge you fractions of a cent.) Why do all stations do it? Because it works; most folks will never even notice they're paying more. And once one station goes with the cheaper-seeming prices, the others must follow suit to remain competitive. —Sally Atkinson