Schema.org Markup for SEO
Structured data or (microdata) allows the search engines to better organize the content on the web. For the first time the three big search engines have collaborated on a shared set of definitions that allow websites and webmasters to tag their relevant content. This means that the search engines and other service providers can use this structured data to provide a better user experience.
There are several benefits for natural search rankings resulting from adding microdata html elements to your website content.
Many one dimensional SEO providers waste energy on non-critical and off site SEO tactics. Microdata is a key SEO tactic that is already and will continue to affect search rankings in the long term. The sooner that microdata is added to your site the better. You will be positioning yourself ahead of the curve!
Along with authorship, adding schema data to your website has become a requirement in the Search Engine Optimization field starting in 2012.