It's been pretty clear for quite a while that Google really likes its authorship signal, and aims to improve it, and make it matter more in search. True enough, the feature does have its benefits when it comes to associating content with certain people, and establishing trust while also improving visibility on crowded search results pages.
However, Google hasn't exactly been rushing to tell people it's going to help their ranking on the search page. It has not been officially established as a direct ranking signal. A new report from Search Mojo CEO Janet Driscoll Miller makes a pretty compelling argument that authorship has is already being used as a direct ranking signal, though she admits it's only a theory. But really, it is a very convincing theory.
I would urge you to read her detailed account of the events that led her to this theory, but to make a long story short, a client (some health-related association) had been apparently hit by the Panda update. The client who had plenty of authoritative links lost its rankings while another site that had plagiarized its content (one of a handful) managed to rank. That offending site was using authorship, despite not being the true author of the content. When they got this site to remove the content, the rankings for the client were improved.
"Some other things to note about this problem include that the offending website is a locally-based business in Texas," Miller writes. "As a searcher based in Virginia, you wouldn’t normally expect to see this local business high in SERPs based on geographic settings."
"However, this site ranked very highly for very popular keyword terms, ranking alongside highly authoritative sites on the given keywords and subjects," she adds. "The site had few, if any, inbound links. After doing some research using the Wayback Machine, it was also clear that these pages were likely added in the May 2013 timeframe, so they were relatively new pages."
Again, you should really read her report for the full story, which makes the argument all the more convincing. She also makes a great point about the potential for abuse if Google is really giving this kind of weight to authorship. Anyone can use authorship and steal content. If that means they're going to rank over the true authors, that's obviously a major issue that Google needs to (and surely will) deal with.
Either way, this pretty much indicates that using authorship is a must. There's no real reason that I'm aware of not to use it, but after this, I'm wondering if there are harmful consequences of not using it.
Note that this report doesn't come from some random conspiracy theorist webmaster, but from a long-time respected voice in the search industry.
The possible Panda connection to authorship is quite interesting, considering that Google (which had previously indicated that it would no longer confirm Panda updates) recently confirmed a new Panda update, which it said included new, unspecified signals. Authority and trust have always been major indicators of quality to Google and are specifically discussed in Google's post Panda content advice.
In June, Matt Cutts was talking about Google finding ways to improve authorship and looking for other ways to use it.
“I’m pretty excited about the ideas behind rel=’author’," he said. "Basically, if you can move from an anonymous web to a web where you have some notion of identity and maybe even reputation of individual authors, then webspam, you kind of get a lot of benefits for free. It’s harder for the spammers to hide over here in some anonymous corner.”
I'm not so sure about that statement in light of Miller's report.
Cutts continued, “Now, I continue to support anonymous speech and anonymity, but at the same time, if Danny Sullivan writes something on a forum or something like that I’d like to know about that, even if the forum itself doesn’t have that much PageRank or something along those lines,. It’s definitely the case that it was a lot of fun to see the initial launch of rel=’author’. I think we probably will take another look at what else do we need to do to turn the crank and iterate and improve how we handle rel=’author’. Are there other ways that we can use that signal?”
He concluded the video by saying, “I do expect us to continue exploring that because if we can move to a richer, more annotated web, where we rally know…the philosophy of Google has been moving away from keywords, ‘from strings towards things,’ so we’ve had this Knowledge Graph where we start to learn about the real world entities and the real world relationships between those entities. In the same way, if you know who the real world people are who are actually writing content, that could be really useful as well, and might be able to help you improve search quality. So it’s definitely something that I’m personally interested in, and I think several people in the Search Quality group continue to work on, and I think we’ll continue to look at it, as far as seeing how to use rel=’author’ in ways that can improve the search experience.”
Clearly this is going to be something for webmasters and SEOs to keep an eye on, and in light of Miler's report, I would imagine that authorship is going to be more scrutinized than ever.