Let's say that you are pricing products and a competitor is charging $19.99. You know that one cent is not going to change the purchasing decision of potential

Let's say that you are pricing products and a competitor is charging $19.99. You know that one cent is not going to change the purchasing decision of potential customers. If it did, you would simply price your product at $19.98 (and maybe get into a price war one penny at a time). Yet you also know that the price ending with a nine will have an impact upon sales. It is not rational, but that's what the statistics appear to say. While it won't have any meaningful impact upon how much money people have to spend, it will have an impact upon where people spend their money.