Google+ Sparks helps users find relevant content when using Google+ search. For example, Tom loves juggling, so he does a search for juggling on Google+. Google searches for pages about juggling and provides the results we believe are most relevant to Tom.
As a webmaster, you don’t need to do anything special to make your content available in Sparks. Just like with search results, though, it's important to make sure that Google can crawl and index your site correctly. Our Webmaster Guidelines outline some best practices that can help you avoid common pitfalls and improve your site's ranking.