It seems to me that most people think that Web Analytics and Search Engine Optimization (SEO) are the same field. Web Analytics and SEO are complimentary fields but not quite the same thing. Let me try to clarify the differences.
SEO is the practice and methodology of optimizing a web site to improve it’s natural search engine results in Google, Yahoo, etc. It combines using a variety of strategies to help improve a site’s chance of getting indexed and raising its ranking in the search results. This, in theory, should help drive more traffic to a web site.
It’s once you start getting traffic on your site, that Web Analytics really takes over. Web analytics is the practice of trying to understand and influence visitor behavior on a web site or campaign landing page through the analysis of web traffic data. This includes making recommendations to improve a web site to optimize it for both the visitors and to increase the likelihood the visitors will do what you intended for them to do on your site (buy a product, download a whitepaper, etc.).
So as you can see the two fields, while very complimentary to each other, are in fact unique disciplines.