Mobile search engines have different bots and algorithms than those used for traditional web search engines. By evaluating your website as if it was being rendered on a mobile phone, they then rank results partially based on how well the page will render on the type of phone that submitted the query.
The best thing you can do to improve your mobile SEO is to ensure that the mobile crawlers and user agents determine that your content will render well and load quickly on any mobile phone.
Mobile search supplies various results and displays forms depending on your type of phone – such as a smartphone or tablet. Google has a special crawler for smartphones, which suggest a future divergence in search results between different types of mobile and for desktop search results.
Google knows the difference between mobile phones
Smartphones have a WebKit browser which is not available in other phones. Google can detect this via the search bot “Googlebot-Mobile” and serve up device specific search results. It is likely they will take this approach with tablets devices as well.
Mobile SEO best practices
Use 100% valid XHTML 1.0 code
Many optimizers on the traditional WWW do not consider using valid code as a best practice. Mobile search engines however may have more trouble digesting invalid code. Be safe! If you validate, mobile search engines won’t have any trouble with your site.
Follow accessibility best practices
Ensure that your content is accessible to anyone regardless of their platform – this includes mobile users and mobile search engines. The W3C’s Web Accessibility Initiative is a good place to turn for the latest information on accessibility. Dive Into Accessibility is also a useful tutorial.
Follow traditional on-site SEO best practices
To improve your mobile search results it’s still advisable to follow traditional SEO best practices as closely as possible. While mobile bots and indexes are different from web search, things like title tags, heading tags and alt tags, keyword-rich anchor text for internal links, etc. are still very important.
It is also a good idea to ensure that each of your pages has at least one incoming link.