Yesterday, Matt Cutts of Google released another video, this one answering why an old site that always ranked well, no longer ranks as well these days.
The question posed was, "How can an older site maintain its ranking over time?"
Matt said that some old sites that have been ranking well for years don't change anything. They leave the 15-year-old template, they don't add any new features or content. They just leave it. This is while other new sites and competitors come into the mix with fresher designs, better user experiences, new ideas and features. Eventually, customers start to leave the old site and go to the new site because it is a better user experience.
Google acts the same way, if you don't continuously improve your sites then why should Google continue to rank it well?
Matt urges older domain names to take a fresh look at their site or else people may leave your site.
Here is the video:
Forum discussion at Twitter.