I'm a big believer in the increasing role of social signals in search. Likes, +1s, and social links are still a noisy signal, which affects their use by search engines. In addition, it should affect how you view your social strategy from an SEO perspective. The bottom line is that you need to focus on authority, your own, as well as relationships with other authorities.
I'll make my case with Facebook since it's the largest of the networks. A quick check on the U.S. Census site reveals the population in the U.S.:
The current number of users of Facebook in the U.S. is around 150 million, or about 48 percent of the population of the country, according to Inside Facebook. That is a lot of people, but it also means that 52 percent of the country is NOT using Facebook.
That's only part of the story. In addition, like all social networks, it turns out that a small number of people are very active in implementing Likes, +1s, sharing content, etc. Classic social network behavior, dating back to the days where forums were the major method for social interaction, shows that 10 percent of the people are very active and do most of the Liking/+1ing/sharing.
Another 20 percent participate, but at a much lower level. The remaining 70 percent are pretty much bystanders. They may have Facebook accounts, many of them may be providing regular updates, but their participation in Likes/+1s and Shares of content is minimal. So now, let's do the math:
- 10 percent of 48 percent of the population is very active, or 4.8 percent
- 20 percent of 48 percent of the population is contributing at a lower level, or 9.6 percent
While 4.8 percent of the population of the U.S. is a LOT of people, we can't have 4.8 percent of the population deciding what should rank highest in search for the rest of us, now can we? Of course not!
Examples of Use of Social Signals for Ranking
Google has made some explicit statements about social ranking signals. There is a page in the Webmaster FAQ that is called The +1 button and search results. Here is one of the key statements from that page:
Content recommended by friends and acquaintances is often more relevant than content from strangers. For example, a movie review from an expert is useful, but a movie review from a friend who shares your tastes can be even better. Because of this, +1's from friends and contacts can be a useful signal to Google when determining the relevance of your page to a user's query. This is just one of many signals Google may use to determine a page's relevance and ranking, and we're constantly tweaking and improving our algorithm to improve overall search quality. For +1's, as with any new ranking signal, we are starting carefully and learning how those signals affect search quality.
So, in theory, the +1 can cause results to be re-ranked, based on one of my friends giving a +1 to a piece of content. You can see that with this example search by me:
Here is the same search result, but now I have added a "&pws=0" to the end of the search result URL to see it without personalization:
Notice how the whartonboston.com web site dropped from the third position to the fifth position? Matt Cutts has also stated that it uses links from Twitter and Facebook in the past, but then he also goes on to point out that author authority matters. This likely means that the number of people who are generating a material signal with their shares or tweets is even smaller than 4.8 percent of the population.
Additionally, Google doesn't have feed level access to the Facebook or Twitter data streams. This means that they must rely on crawling to find links shared by users. However, that access is pretty limited. Google can't see share data, and my examination of the source of the Facebook site suggests that they can't easily get a complete list of a Facebook user's friends, making the determination of author authority difficult.
Bing has a feed-based relationship with Facebook, so they get all of that data. As a result, Bing is doing more with those signals than Google. For example, if I search on Seattle, I'll see which of my friends live in the area:
This is potentially very useful, but not a re-ranking signal. Another example used to occur on Bing when I searched on the "New York Post", where Bing would surface the most Liked articles on the paper's website:
This is a form of re-ranking as you see two of the paper's article surfaced within the SERPs. However, performing the same search today shows that Bing may have stopped doing this for now:
What we see instead is a link for "Recent activity from New York Post". This suggests that Bing decided the "wisdom of the crowd" approach of showing the most Liked articles wasn't the best use of their Facebook data stream.
How Then to Use Social Media?
There are many reasons to engage in social media, including those that go well beyond SEO. You can get significant direct traffic, you get branding value, exposure to your target audience, and more.
If you want to be a significant player in your industry than social media needs to be an important part of your mix. From a pure SEO perspective, getting a handful of Likes and +1s won't really move the needle. Even if the search engines find a few shares/tweets of links to your content, it probably won't have a huge impact either.
However, getting an authoritative person in your space to share your content will probably be a big win, and this is an excellent goal for your social media campaigns. Similarly, building your own audience and establishing your own authority is also a big win. These are the steps that give you access to large audiences. As noted above, the payoff is visibility with your target audience, branding value, and traffic.
This provides more weight to the links you share, and to your content when other authorities share it. Now for the big SEO payoff - when large audiences of active social site users see great content put in front of them, they link to it from the real web. My recent interview with Bing's Duane Forrester received a strong response from the social networks and ended up netting 730 links, according to Yahoo Site Explorer.
You can see the impact by using a fairly generic search query like "Bing ctr" where this page ranks No. 2 in Google and No. 3 in Bing (personalization was turned off when I did the searches). This where the real win comes then, both from a pure social strategy or a social for SEO strategy point of view.
Focus on authority. It is where the money is.