Over the last 18-months Google has changed the way that it ranks web sites. These updates were called Google Panda and Google Penguin. The two algorithem changes affected search engine rankings for more than 20-percent of all web sites. If you have been hit by either of the Google updates you may need to optimize your web site and/or look for a good SEO Plan.
Google made the changes in an effort to provide better and more revelant search results. However, many sites that have enjoyed top rankings for years have been affected and seen a drastic reduction in traffice to their web site.