Psychological Pricing is based on the belief that customers tend to process a price from the left-most digit to the right, and so will tend to ignore the last few digits of a price. It is the practice of setting prices slightly lower than rounded numbers, in the belief that customers do not round up these prices, and so will treat them as lower prices than they really are. The theory of psychological pricing is controversial. It is a strategy that retailers can take advantage of, whether they operate online, offline, or in multiple channels. Psychological Pricing is a tool that retailers can use to subconsciously increase the chances that a customer will make a purchase.