Before Google Reader was released, Gmail's "inbox zero" message used to be: "No new mail! There's always Google News if you're looking for something to read."
Now that Google focuses on developing Google+, a modern version of Google Reader, Gmail's new message is: "No new mail! See what people are talking about on Google+." The links sends Gmail users to the "what's hot" section of Google+ which "highlights selected content thought to be exemplary, interesting, and appropriate: showing you serendipitous and diverse information".
From Google News to Google Reader and now Google+, Gmail illustrates three different ways to read news. Google News ranks and clusters articles from the web, Google Reader allows you to read news from your favorite sites, while Google+ lets you read the articles shared by the people you follow. From news that are important to everyone to news that are important to the people you trust.