I like to perform a keyword analysis around twice each year, along with a look at how the SEO is doing on my web sites. As the search engines announce changes to their ranking methods and algorithms on a regular basis, it is good to keep up with them by running some numbers and testing a few things to make sure the web site is at the least remaining in compliance, and in effort to reach for improvement.
I can do this for you at your convenience providing you with a keyword analysis report, suggestions for improvement, reports on popular keywords that are trending that relate to your web site and an overall picture of how your SEO is looking.