W3C Compliance and SEO
"My website is W3c compliant, does it help to acquire rankings into SERPs?"
Well ... Yes and No.
Yes .. why?
W3C compliance is a good thing for your website. It will ensure that it is accessible for the disabled, it will also ensure that your website is accessible from a large numbers of devices such as PDAs or mobile phones. It is also a good thing to know that your website is going to be displayed correctly and will work properly regardless of the browser used on the client side (Yes, sometimes, a website can look fine on Explorer, but not on Mozilla, or reciprocally).
If your website is W3C compliant, search engines will have no problem crawling it and you can be sure that no technical problem will be preventing your website from acquiring positions.
Well simply because if the content of your website is not relevant or well emphasised, it has no chance to acquire a good ranking.
A compliant website will ensure, at least, that your website has no technical problem. It is a lot easier to optimise a website which is well developped from scratch. So if you can, you should develop a compliant website but this will not be enough to rank high on SERPs. Content is still very very very important.