A study by Blue Nile Research has shown that rich snippets may increase the chances of the second search result being chosen over the first result by 26%. Rich snippets is added to search results by using structured data or schema markup in your html code. You can use it to add images, videos, review stars, recipes, events and a number of other things in search results. It is important to note that even though you have this structured data on your website, it is up to the search engine to display what it wants.
To see the full research study visit Blue Nile Research