0:56

And the way that works is that the PageRank is split

Â among the outgoing links.

Â So, in this case,

Â I'm showing a page with F of X being the PageRank that it's voting out.

Â And it gets split between these two pages.

Â Now to be fair, in practice, it may not be exactly 50% to each of the two lengths.

Â It might be slightly different based on where a link is placed on a page, but for

Â purposes of this discussion, you can just imagine it's exactly equal.

Â So far, the picture looks pretty simple.

Â However, here's where it starts to get a little bit more complicated.

Â So, imagine you have page A over here on the left that links to pages B and

Â C shown on the top right and bottom right.

Â And so far, it's straightforward.

Â But now page B links back to page A.

Â So now the math starts to get very complicated because page A has voted some

Â page rank to page Y, which votes some of its page rank back to page A.

Â Which makes page A as page trying to go up, but it's voting some of that to page

Â B, and it gets very iterative and becomes

Â a very complex calculation to figure out what the final page rank values are.

Â And this is a problem that search engines solve all the time.

Â And in fact,

Â it gets a lot more complex because the real web looks something more like this.

Â In fact, even this diagram that I'm showing you now is very simplistic.

Â The real web consists of hundreds of trillions of web pages all linking to

Â each other, this massive array of links going back and forth.

Â Google and other search engines are able to resolve those calculations and

Â figure out the PageRank value for each of the pages on the web.

Â 2:55

Couple of important points you should know about that.

Â First of all, it's not the same as real PageRank, what's been shown there.

Â It's actually a logarithmic representation of the real number of PageRank.

Â And what that means is that if you have something, which Google calls PageRank6,

Â it's in theory something like ten times more important than a PageRank5 page.

Â And this is going to be important point that I'm going to

Â emphasize more as we go through this course.

Â And it's assigned to web pages, not sites.

Â There's no such thing as a PageRank for a domain or a site.

Â That's an important thing for you to remember.

Â However, this PageRank that we see in the Google toolbar is no longer updated.

Â So the metric you see there is obsolete, and

Â the only reason that I brought you through all this is I want you to understand that

Â you can't rely on the Google toolbar as a way to get this kind of measurement.

Â So now I want to give you an example, now that we've gotten this far.

Â Ask yourself a question, if you have 10,000 PageRank2 links and

Â 1 PageRank7 link, which of those seems more valuable?

Â 10,000 links is an awful lot of links.

Â One second challenge question for you, if you get 300 PageRank5 links,

Â are they more important or more valuable than 5 PageRank7 links?

Â Well, here's the true story.

Â Turns out that 1 PageRank7 link is actually worth quite a bit more than

Â 10,000 PageRank2 links.

Â So, if you can see the math here, since 1 PageRank7 is worth 10 PageRank6, and

Â that's worth 100 PageRank5 and so forth, 1 PageRank7 link is actually,

Â in theory, worth 100,000 PageRank2 links.

Â 4:39

Remember I said earlier on,

Â 1 link can be worth 1 million times more than another one?

Â So this is just really an illustration of that.

Â And you can see the same thing with my example over here on the right,

Â where 5 PageRank7 links is worth more than 300 PageRank5 links.

Â Now keep in mind, I keep emphasizing that 1 PageRank7 or

Â 1 PageRank6 is ten times more valuable than 1 link that 1 PageRank step down.

Â That's just an approximation, but you should keep it in mind and get across this

Â notion that one link can be worth a heck of a lot more than another one.

Â So, as I mentioned, Google no longer updates PageRank,

Â that you can see in the toolbar, but they do still update the real PageRank,

Â and links remain a major part of their algorithms.

Â The three main tools I like to use to get information on links

Â are Open Site Explorer, Majestic SEO, and ahrefs.

Â Each of these are tools that you can use to get information about

Â who is linking to your site or the sites of your competitors.

Â And with them, they offer metrics similar to Google's PageRank

Â which you can use to get some idea of how to value links.

Â So for example, Moz's Open Site Explorer has a metric called Page Authority,

Â which is their approximation of Google's PageRank.

Â And they calculate it in a method very similar

Â to what Google is believed to be using to calculate PageRank today.

Â Moz also has a metric called domain authority.

Â which is an estimate of a site's overall authority or

Â you consider as the authority of the entire domain.

Â And remember I said earlier, Google does not have such a thing

Â as domain PageRank or PageRank for an entire site.

Â But Moz does have their own calculation along those lines.

Â For Majestic, Majestic SEO,

Â they have their own calculations called Trust Flow and Citation Flow.

Â These are also meant to be calculations of the importance of a link.

Â They're not calculated by the same type of algorithm as Google uses,

Â but they can still be very valuable in helping you understand

Â when one link is more important than another.

Â And then ahrefs also has their own measurements.

Â One's called URL Rank, and then they also have a Domain Rank, as you can see here.

Â Very similarly, these are used to help you understand which links are most important.

Â One more thing to cover about links, which you should really have in mind when you're

Â looking at the value of a link, and that's show relevant it is.

Â So, if you have a page about used Ford Mustangs, and you get a link

Â from a casino gambling site, well, that's not very relevant, is it?

Â So that's pretty low value.

Â Contrast that with a link from Car & Driver Magazine or FordVehicles.com, well,

Â that last one is a made up domain.

Â But anyway, those links clearly seem a lot more relevant.

Â So you're getting a vote here in a sense from an authority on a topic,

Â Car & Driver Magazine in this case, to your page on the same topic.

Â Clearly, that should carry more weight, and the search engines understand that.

Â Another thing to think about is what are the authoritative sites in

Â a given market space?

Â So here, I'm talking about topical authority.

Â Imagine you have this picture, which is all websites about used cars.

Â And some of them, the three that I've highlighted in the blue circles,

Â they seem to be getting links from a large number of sites in this space.

Â Those are the ones that you might think of as being the authorities on that topic.

Â So links from those sites probably carry more value as well.

Â So if you back up and try to have a way to think about

Â how you would assess a link's value, here are some things to think about.

Â First of all, I do like to use Domain Authority and

Â Page Authority from Moz as one basic measure, but

Â you can certainly use the Majestic and ahref's measurements as well.

Â As I've said several times, keep in mind,

Â one link can be worth 1 million times another.

Â That's going to be really important as we talk through content marketing.

Â Topical relevance is also a very large factor, so

Â the more relevant the link is, the better.

Â And then, just for

Â me, I like to place the most weight on domain authority as a metric.

Â To me, that says the most about the value of a link.

Â So if a page on a website links to me and

Â that website's Domain Authority is higher, I like that.

Â And then my second theory metric is Page Authority.

Â And that's the one I like to look at next.

Â In this lesson, we talked about what makes one link more valuable than another.

Â We also talked a bit about how you can get a determination

Â of a link's value for yourself.

Â In the next lesson, we'll start to talk about link building,

Â which is what SEO professionals use to focus a great deal of energy doing

Â to obtain links to their sites.

Â I'll also provide you some guidelines that will help keep you from going about

Â building links to your site in a manner that search engines don't like.

Â