Compiled By Frank R. Chloupek According to a recent study by NFO WorldGroup, a Greenwich, Conn.-based provider of research-based marketing information, 31% of consumers change their e-mail addresses each year. Furthermore, many of those who change their e-mail address do not notify all of their personal or business contacts (including Web sites) of the change. "The rate of e-mail address turnover continues unabated from the pace we first identified in September 2000," says Matt Blumbers, CEO of Return Path, one of the sponsors of the study. "In addition to the impact on consumer relationships identified, there is a real and significant subsequent financial impact on reputable businesses that rely on e-mail to communicate with their customers." The factors behind a change of e-mail address include a new Internet Service Provider, job changes and attempts to reduce spam. While the average consumer registered their e-mail address with 12 Web sites, they notified only about six when their address changed. Twenty-two percent didn't notify any Web site. The study was based on responses from 1,015 members from NFO WorldGroup's online panel representing e-mail users over the age of 18. It is representative of U.S. households that utilize e-mail.