How important is w3 validation for search engine rankings?
Depends on the search engine.
A page that is written in valid code is well on its way to being accessible, as well (but the two are not interchangeable!).
Google doesn’t just look at inbound links and mostly ignores meta tags (as both have been massively abused by spammers) - in fact, Google actually traverses pages for contents. If the contents is placed in valid HTML, your chances will be somewhat improved. The second step is using SEO (Search Engine Optimization) - the best way to do that is to write valid *and* accessible code. Things like source ordering and correct *use* of HTML are very important.
Do a search for "SEO", and find yourself a whole new world of demands ragrding HTML.

L S said:
I wouldn’t think there is a direct link between validation and rankings. Validation is about looking for errors in your code and obviously if your code works correctly it will make it easier for bot crawlers to find their way around your site but appropriate meta tags and submitting your site to search engines would matter more to increase your ranking.
References :
Animate L said:
It’s important to make your site w3c, but you should focus more on Link Building. Link Building is the most important factor, and if you work well on it, then it won’t even matter if your page is w3 compliant or not, as Search Engines consider Link Building a Top Priority. Another important factor is the Title tag and to write good content in your pages. You can get much more details from High Rankings Forum: http://www.highrankings.com/forum
Animate Logo Team
http://www.animatelogo.com
References :
Mehdi said:
Depends on the search engine.
A page that is written in valid code is well on its way to being accessible, as well (but the two are not interchangeable!).
Google doesn’t just look at inbound links and mostly ignores meta tags (as both have been massively abused by spammers) - in fact, Google actually traverses pages for contents. If the contents is placed in valid HTML, your chances will be somewhat improved. The second step is using SEO (Search Engine Optimization) - the best way to do that is to write valid *and* accessible code. Things like source ordering and correct *use* of HTML are very important.
Do a search for "SEO", and find yourself a whole new world of demands ragrding HTML.
References :