It's a search engine. It's a social network. Google is a lot of things, and its parts are interconnected.
First, some background
The same month that the Google+ social network was launched, Google announced a new way to link writers to content they create: Google Authorship. Along with personalized search results, Authorship became a second direct connection between the social network and Google search results.
Until June 24, 2014, on its search results pages, Google showed author pictures (taken from the Google+ profile page), the name, and the number of G+ circles the author had been added to.
It looked like this:
Researchers found that when an author's picture appeared next to a search result, the clickthrough rate for the search result went up. The "rich snippet" for Authorship was increasing traffic. One study showed a lift of 35%. Authorship was suddenly a way to get more traffic from the same rankings.
On August 28, Google removed the author's byline as well, so that the same search result looked like this:
Andy Crestodina is the Strategic Director of Orbit Media, a Web design company in Chicago. He's also the author of Content Chemistry, An Illustrated Guide to Content Marketing. Connect with Andy on Google+.
LinkedIn: Andy Crestodina