In this lesson, I'll dive into one of the most common misconceptions in the world of SEO, and that's the value of links contained within social media posts. I'll show you the value that they actually do bring as well as dispel some myths about social media and link building. And if you watched the last module, you'll remember that I talked about how social media sharing can help build your audience. This is absolutely true. So here I am showing at the top left this notion of publishing a post on your site say, sharing it in your Twitter feed, that's where you see the red one and then it gets in front of your own audience, which is already good. But somebody in your own audience, in this case Jack Stickman I'm showing below, might retweet your post and now you're in front of Jack's audience. And some of the people in Jack's audience might start to become part of your audience. This is one of the best things about social media and a very important part of any holistic content marketing strategy. And I also talked previously about how social media sharing can help drive links to your site. So here I'm showing the notion on the left, the publishing a high-value post. It's shared on social media, and it's so good that it helps your social media presence get new followers, fans, shares, and etcetera. And then, that's great but now because I've got in front of those people, I'm getting traffic, links, and new subscribers back to my content. And there it is, the magic links word, creating value from an SEO perspective for your site. Well what confuses this story a bit more is that MOZ, which is a great organization, published fantastic studies on search engine ranking factors, did a study back in 2013. And in that study they talked about how Google +1's was a major ranking factor. The way they did this is they looked at a large number of webpages and they looked at a large number of attributes of all those pages, and they developed correlations between high-ranking pages and which pages had more of each of these attributes. It turned out that many of the pages that ranked high tended to have a large number of Google +1s. Which by the way, that isn't the way Google talks about it anymore. They think of it as you just re-sharing a piece of content. For sake of historical accuracy it was originally +1s at the time. And the notion that I'm trying to draw for you here is an equivalent notion is whether or not a link in a Google plus post will have value. Well, at the time it was the number two ranking factor, according to this correlation study. Well Searchmetrics did a very similar one at the same time, and also showed Google +1s as being a very powerful ranking factors. So, that's it right? So we just need to start sharing our stuff on social media and we're off on our way to SEO greatness. Not so fast. You've got to be careful with correlations. Turns out, a very strong correlation and drowning death and consumption of ice cream. And the reason is, they both happen while it's hot outside. You're more likely to go swimming when it's hot outside and therefore, it's more likely you'll have more drowning death. And of course, you're more likely to consume ice cream when it's hot outside. But it doesn't mean that one causes the other. By the way, MOZ and Searchmetrics were both very clear when they published their studies about the differences between correlation and causation. So let's start to talk about some of the things that limit search engine's ability to use social media platform signals as a ranking factor. First of all, if you're wondering if Facebook likes might have some weight, search engines can't even tell what pieces of content you liked. Yes, there may be a widget on that page where you can see how many likes the page has gotten. But it doesn't really add any value to the search engines if they don't know who did the liking. And then if you go at a Facebook post that shares a link to an article on some other website, those links are marked as nofollow. And you might remember from one of the earlier courses in this specialization that when a link is marked with nofollow, it tells the search engine to pass no link value through that link whatsoever. So Facebook has marked all the links outgoing from their site, from within social media post has nofollow, game over. Link has no value. Same thing is true on Twitter by the way. All their links are marked as nofollow. And for that matter, it's also true on Google+. This links are all marked nofollow as well. So that's it, right? Actually there's one other thing that I want to share with you about why it is that Google and other search engines don't see a lot of value in social signals. One of those is well the signals are coming from third party platforms and the visibility of that data is controlled by that third party. A search engine can't build their ranking algorithm on a signal that could be turned off like a switch by someone just like that and boom it's gone and their ranking algorithm is suddenly broken. That would be giving way too much power to the other party so there's no way that Google can do that. But that's actually not the end of the story, turns out that there is one small way that you can get some influence from something that you do on Google+. So let's say you using your Google+ account share a piece of content through your Google+ in a Google+ post. So you write this Google+, post you include in it a link to this other content, okay. So just keep that in mind, or you follow someone's Google+ profile. Well, in either of those cases, there's some possibility that you might experience personalization of your Google search results. So what I'm showing you here, is a post that ranks number two for me when I'm logged in, into Google+ or into Google in general. When I'm logged out, that post ranks lower. And the reason why there's a ranking difference is because I shared this article at one point in time. And so that indicated to Google that I liked it. And that's why they've given me a little bit of personalization and tend to show that higher for me. In this lesson, I tried to show you that simply sharing links in a social media post is not a way to get links to your site or drive your SEO. This is true for many reasons. Social media sites block the flow of PageRank with nofollow tags. And also, search engines can't be confident that links in social media posts are truly editorial votes to your site. And lastly, they can't be dependent on a third party platform for their ranking algorithms. In the next lesson, I plan to review basic demographic information for many of the major social media platforms. This information can help you decide where you should focus your social media efforts.