We have a client right now whose ranking took quite a dip lately. As we continue to help them fix errors documented in Google Webmasters, one of the glaring issues is 404 Page Not Found errors. As companies migrate sites, many times they put new URL structures into place and old pages that used to exist do not exist anymore.

This is a HUGE problem when it comes to search engine optimization. Your authority with search engines is determined by how many people are linking to your site. Not to mention losing all the referring traffic from those links that are all over the web pointing to those pages.

An additional problem is...