Your market changes. People's needs change. Technology changes. Society changes. All this ensures that something on your Web site will appear dated or stale. The moment this happens, the overall marketing value of your site begins to decline. Not every visitor may notice or care, but some do. We've all seen wonderful sites that carried some trend or news update section with a date that was three months old. So change it.
Excerpted from 101 Internet Marketing Tips For Your Business