Consider this: 30 million people change addresses every year. That means as much as 25 percent of your mailing list addresses can potentially be outdated. Having mail returned costs your business money. If as much as 25 percent of your mail can be returned or never received due to the wrong information, that means as much of 25 percent of your spending has literally gone down the drain. That makes being on top of your customer’s information very important. Another waste of money is doubling up on mailings. This can also affect the mailing lists you buy. Merge purge software can help keep your mailing lists clean and effective.