another relevant piece of information:

https://developers.google.com/structured-data/?hl=en&rd=1

"Promote Your Content with Structured Data Markup

"Structured data markup" is a standard way to annotate your content so machines can understand it. When your web pages include structured data markup, Google (and other search engines) can use that data to index your content better, present it more prominently in search results, and surface it in new experiences like voice answers, maps, and Google Now.

Structured data markup makes your content eligible for two kinds of Google features:

Enhanced Presentation in Search Results: By including basic structured data appropriate to your content, your site can enhance its search results with Rich Snippets, Breadcrumbs, or a Sitelinks Search Box.

Answers from the Knowledge Graph: If you're the authority for certain content, Google can treat the structured data on your site as factual and import it into the Knowledge Graph, where it can power prominent answers in Search and across Google properties. Features are available for authoritative data about organizations, events, movie reviews, and music/video play actions."