Here's a hint for you guys: +1s, tweets and likes don't work for SEO, but social shares (when somebody actually links to your post from Google+ or Facebook, or shares it on his/her own wall) actually work wonders.
Also, I see so many people tackling backlinks and Penguin, when in fact their rankings are plummeting because of Panda...yes, that's right, PANDA, not PENGUIN. I can only tell you that Panda is mostly driven by user search metrics (Google owns Chrome and has invested a lot of money into Firefox, A.K.A - they have the backend data on Firefox users as well) - hire a UI/UX designer make the user experience the best possible, so that the user metrics increase in your favor. There are some tools out there which you can use to manipulate these metrics.
Forget about backlinks, you only need around 10 of them which are relevant (hint, a private blog network consisting of expired domains with high DA, PA and Trust flow without a long record of being expired)- that's enough for the backlinks. Then focus on social, but not those crappy likes and +1s, but on real social link sharing on people's own walls. Finally, focus on good user experience to increase your user metrics stats, or manipulate it.
The way to rank these days is very simple, but you have to get out of the "old days" mentality.
1. Don't write the articles around keywords, but rather a topic. Pages that I rank have 0% keyword density - that's right - 0%. But they are all themed properly. Use tools for that (I won't promote them here, but you know which ones i am talking about). I'm not here to preach some white-hat nonsense, I'm telling you this from my own experience. Google is moving away from the keyword driven queries, and moving into the field of interpreting queries. Hummingbird was the first step.
2. Try to sculpt the Pagerank on your site by creating thematically tight categories. You could call it siloing, but I wouldn't go that far anymore, since I've seen some of the sites tank if I tightened the silo too much. I'm not talking about the browser Pagerank, but rather their internal Pagerank, which is nothing but a simple linking stream of your site.
3. Hire a good UI designer, or try to do it alone. I'm a student of multimedia engineering, and my college collaborates with Google on some projects here in my country. You wouldn't believe what you can find out if you can read between the lines. People are saying that the design doesn't matter and that links are all that matters, but I can assure you, this couldn't be farther from the truth. Sure, they can't read the design directly, but they can read it by data that the user gives them (even if he/she isn't logged in). Bounce rate is just a drop in the sea here, and I'm not talking about the flawed bounce rate metric in the GA. I'm talking about the real bounce rate.
All in all, if your site doesn't rank well, and you don't know why, read the points above. Also, keep in mind that some of the penalties and triggers are much more complex than what people are discussing on blackhat forums. For example, I know for a fact (don't ask me how I know this) that Panda and Penguin are working in tandem; this means that if your site is targeted by Panda (and most of the sites owned by blackhatters are, they just don't realize it, and think that it's Penguin, simply because their "GA bounce rate" says it's "good") every bad link that you point to your page increases the chance of triggering the Penguin exponentially. Although they are not directly connected, you can see where this is going.
Anyways, this has been my rant.
