With so many sources posting content on the web, Google is always looking for ways to sort the wheat from the chaff. It has algorithms to sort articles by keyword density and social reaction, but there's one thing it values above all others - the human factor. Google Authorship is a way of tying a human identity to the content you create on the web, thus giving it an extra boost in terms of being considered a reliable source.
Like much of Google's systems, Authorship is mostly a behind-the-scenes thing, but it does have some very practical applications for users. The main benefits are:
This is becoming more and more important as Google continues to prioritise the user experience and human endorsement of content - and since it's heavily tied in to their social media network Google+, they have a vested interest in making it enticing for people to use.
Once you have a profile with a photo set up on Google +, there are two ways of going about linking your account and your content. If possible, you need to use the same email on both your Google+ account and the domain that content is on - for instance firstname.lastname@example.org will help Google snoop out any blog posts published on the Company website. However this isn't always available, and a special link must be made in the author bio or somewhere in the article that points to your Google+ page. You then need to go into your Google+ profile settings and list yourself as a contributor to that website as well.
Google Authorship ties your web writing together, proves you are willing to put your name to your words and looks set to continue as a defining factor in how Google values content.