What does Website Accessibility have to do with SEO?
Proper use of standards and bleeding edge best practices makes sure that not only is the copy marked up in a semantic fashion which search engines can interpret and weigh without confusion, it also skews the content-to-code ratio in the direction where it needs to be while forcing all of the information in the page to be made accessible, thus favoring the content.
We’ve seen several occasions where the rebuilding of a site with standards, semantics and our proprietary white hat techniques improves the performance of pages site-wide in the SERPs.
Essentially what is being stated is a fairly logical conclusion, reduce the amount of code on your page and the content (you know, the place where your keywords are) takes a higher priority. Additionally compliance will, by necessity, make your site easily spidered and additionally allow you greater control over which portions of your content are given more weight by the search engines.
Once you’re done you’ll be left with a compliant site that not only will be available on a much larger number of browsers (increasingly important as browsers such as FireFox gain more and users) but you’ll have a site with far less code that will rank higher on the search engines because of it.
To be sure, W3C validation is not the “magic bullet” to top rankings. In the current SEO world there is no one thing that is, however as more and more website are born and the competition for top positioning gets more fierce it’s important to take every advantage you can to not only get to the first page but to hold your position against those who want to take it from you as you took it from someone else.