"According to the company, Gmail users who are utilizing Priority Inbox are spending about 43 percent more of their time "reading important mail." Google added that Priority Inbox users overall are spending 15 percent less time sifting through e-mail than those who aren't tapping the feature.
Read more: http://news.cnet.com/8301-13506_3-20024822-17.html#ixzz17Rp8z3t0"