The number of mobile internet users is increasing each year with great speed, so it is easy to figure out that the search traffic trends over mobile devices have increased as well. Since more and more people are using smart phones there is little need to create mobile versions of the site and to optimise them, although we would advice that you do so.
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Most say that it doesn’t. This likely stems from the fact that w3c validation is confirmed to have no impact whatsoever on page rank and SEO.

