Just Google it! Advantages are mainly visual and generally help to increase clicks on organic results, but there aren't SEO benefits.
There are mainly three benefits of using Rich snippet that I would like to share with you without changing any word directly from SEOMOZ. 1) Drawing a user's attention to your relevant result. 2) Providing instant information as related to their query. 3) Increasing click-through rates and lessen the amount of bounces due to not searchers not finding the content they were looking for. Credit: SEOmoz.
There is no proof yet, but it makes sense that setting up authorship on a site may help SEO in the future if it doesn't already. Think about it. A lot of SEO's are just out to create a site, send a billion links to it and make a payday. And I don't think most of those guys/gals would go through the trouble of setting up authorship on such a site. I think it adds trust in the eyes of Google. How much...who knows. Who even knows if it's true, but why not do it. Setting it up is really easy, so just in the small chance that it is a benefit...why not!
It is always helpful to get your website listed in Google result with rich snippets as it provide more information about your website. It helps visitors to land directly on few of your popular pages and it also gain trust.
A rich snippet is essentially just a small summary of the data that a user can expect to see on a page. They can come in many different forms, but all serve the purpose of providing basic information quickly so a user does not have to click the webpage and go through the process of loading. In other words, people are more likely to click on a result with a rich snippet than a site without. They really draw the attention of readers, and they can help reduce your bounce rate because people will know they are interested in your site before they click.