We're using way too much laundry detergent, and here's why

Laundry detergent is a $7 billion industry in the U.S., but a lot of that money and soap goes down the drain as people use more than they need. One of the main reasons for this waste are the measuring cups that come with liquid detergent. The Post's Matt McFarland asks D.C. residents how they do their laundry.