Is there a page on your site that is showing up as the landing page for referred visitors from search engines surprisingly often? This was the case for MacDuggal.com. I was mystified as to why a post indicating the dates and location for our August fashion show was getting a lot of site entrant traffic. I could not understand why there was interest in finding information about the location and dates of a fashion show held 4 months ago.
After a bit of research, I uncovered the fact that the traffic was coming from auto complete. The reason this result was getting clicks was because Mac Duggal is a designer of prom dresses, and variations on terms including "Mac Duggal prom" are sources of frequent searches. When "Mac Duggal prom" is inputted into the Google search box, auto complete has been adding in "2013" However, since the 2013 collection was only recently released, and "2013" was not on any other places on the website, Google selected this outdated page as the top Mac Duggal result.
As the above example demonstrates, it can be useful to audit your search engine auto complete results. Input both your brand name and queries that are generating significant search engine referred visitors. Check to see that you have pages that are optimized for the results of auto completes and are providing an appropriate user experience for a visitor that clicks on the auto complete result.
Also, check on Bing auto complete results. They can sometimes differ quite a bit from Google's. In this case, Bing is adding 2012 to the query.
Auditing the auto complete results being generated by search engines should be a regular activity. Check to see that pages on your site are optimized both to rank well for search and to provide an intuitive user experience for visitors that arrive via clicking on auto complete results.