Here’s the simple lesson we learned—which others were learning at the same time and which eventually changed the way retailers sell and customers buy all across America: say I bought an item for 80 cents. I found that by pricing it at $1.00 I could sell three times more of it than by pricing it at $1.20. I might make only half the profit per item, but because I was selling three times as many, the overall profit was much greater. Simple enough.

