If the traffic of your site dropped off the cliff after the Penguin update last April, then social signals and associations might be your answer.
Never mind what Matt Cutts says; Google has to fight SEO-links to maintain the quality of their search results, which means they look for patterns to identify cheap crap or dirty tricks, but at the same time they also look for indicators to identify genuine quality links.
So while the Google Panda update was about de-indexing crappy pages (= you losing your links) and the Google Penguin update about the balance of low value links versus high quality links within your profile, Google has also been looking for ways to identify genuine quality content better. That's why they came up with 'associations'.
So what are associations?
Well, we're still talking about links, but its how Google read those links and uses them that is new, which is why we call them associations and social signals, instead of links. But believe me; we're still talking about links!
As always it comes in layers:
First of all; it's all about public profiles, as well in the social media as other platforms like blogs and forums; the links from and to other people's profiles are your associations, so step 1 is to set up those profiles.
But then there's the next layer; your content as an author, here Google will see a link from your content to your profile (s) as a stamp of approval, according to the trust your profile has of course. (read it again; I said; a link from your page to your profile, not the other way around!)
So that's why there's the third layer; using your profiles to gain that trust, and then we're of course talking about making connections with other people in your niche that already gained trust themselves and getting likes for your content and profiles.
As a SEO company we do create more than just 1 set of profiles, we also set up support accounts. We do this to follow the main author, so we can give your content at least some likes, votes and shares. But that's just minimal to get the process started, to gain real trust, to get real likes you simply need to make sure that your content is worth it. We can give it a little push, but the only way to really score in places like Facebook is by standing out, by actually bringing something of quality. This is why Google is more and more relying on those social signals (likes, shares, etc.) to diversify 'fake' content and 'real' content.
Beside that, since Google has been doing the Panda updates; de-indexing crappy pages from their index based on algorithms designed for each specific platform individually and the Penguin update; if on April 24 2012 you still have way more crappy links in your total link profiles than natural, quality links, then they devalued your site as a whole and you lost almost all of your keyword positions.
As in; more than ever it's important to have quality links. One simple way to do so is to set up social profiles, use them wisely and then make sure that all your off-page content is linking to your profiles and vice versa. This way you turn your crappy links into natural quality links which will make the balance of your total link profile tip faster, as you take away crappy links and add good links at the same time, so you can get your rankings back.
You also have to do so for your own web site; you absolutely need social buttons on your site, not just so people can easily like or share your content, but also to make the association for Google; that's what's new here; Google will read links pointing from your site to a trusted social profile as a stamp of approval, as a signal of genuine content.
See it this way; social signals do not give that much SEO value, but without them you lose a lot of the SEO value you get from other type of links. It's about 'proving' to Google that you're genuine to avoid losing your SEO value.
Here the top 10 social media site;
Of course there are more, a lot more, but like all link building tactics since Panda and especially Penguin; massive amounts of cheap crap, just does not cut it anymore. It really comes down to selective link building; combining all different tactics and using only the quality sites, and of course only as long they are related or can be made related to your site. (We do use a few more, but those do not require registration; we use your Facebook, Twitter or Google+ account to log in)
So, to conclude; you need to have quality content to start with, then by using your social profiles to inter link as well your on-page as off-page content, you create a web of associations, which will lead to your profiles gaining trust and so giving your content a stamp of approval, but of course only as long you stay away from automated programs or cheap SEO services, but simply do what you would do as a normal human being; just be more efficient at it … as in; let us do it for you.
Ok, just 1 note: I did say 'may' … if you have no quality content, no natural links, no high-PR links, but only low value, crappy links then you should redirect your site to a new site, that actually does the trick just fine.