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.
Eric EngeCo-Author of "The Art of SEO"
