The Data Warehousing Institute, a Chatsworth, Calif.-based trade organization, says that about 2% of all customer records become obsolete each month due to errors in original information. In addition, an estimated 43 million Americans move each year. Those factors, plus the error rate in most databases, cost U.S. corporations $600 billion or more annually.

“If you do the math, about 24% of any direct marketer’s customer prospect list is going to be obsolete over a year’s time,” says Jack Schember, marketing manager for Melissa Data Corp., which sells software systems for marketers.

Melissa Data’s Address Object program, available for $3,000 to $9,000 depending on the user’s scale, is designed to instantly catch and correct data errors by matching the address entered by applicants online with actual, verified addresses.

The USPS also offers its National Change of Address service, which is inexpensive and licensed to may third parties such as Melissa Data, to make sure direct marketers’ prospect lists are up to date with consumers’ relocations.

However, “the number of direct marketers that fail to use this service is unbelievable,” says Schember.

The total cost of sending to an incorrect address—plus correcting it—can go as high as $10 per customer file, according to Schember.