Page authority questions?

[SherWeb]

I've been analyzing some IT communities ...in order to check how relevant is the page authority vs PageRank. I found one main site which is organized by "communities'..and every community is a sub-domain. The root domain has an authority of 90/100 which it should be great......so the sub-domains "inherit" part of this authority.... Until here everything seems to be perfect. However, I went deeper and I picked one of these communities. Analyzing the "Linking Root Domain" I discovered it only has only 5 root domains pointing to its home page. Those 5 Root Domains have generated more than 134k links. That doesn't seem to be "natural".

Checking those 5 Root Domains I discovered that they have been registered by the same Root Domain site.

Ex:

Main domain: Domain.com

Community1.domain.com

Community2.domain.com....

Linking Root Domains:    DomainXY.com

DomainABC.com

DomainRST.com

DomainFGH.com

DomainOPQ.com

It seems to me that it is easy to cheat  the authority domain score. Just creating others sites developing the same topic and generating back links to your main domain

[MarketingOfAmerica]

What is the site that you analyzed?  Comparing PA versus PR isn't going to help you btw.  Page rank can be manipulated as well very easily.  For example I seen a pr4 for sale on  godaddy auctions today for $5.00.  The site had 0 backlinks.  The site has been down for 1 year.  So how does it still have a pr4?  Pr4 to me isn't a good indication to link to anymore at all.  People buy high pr sites daily and can make them look like they are 10 years old fast.  I count on PA and DA to give me a good indication, because most people aren't cheating DA and PA if there is truly a way to do it.  Also, to cheat it, you would just be cheating for your own confidence and it wouldn't do anything to help you rank better if you cheated yourself to a high one.

So to sum it up, I feel that PA or DA is much more accurate and up to date than PR.  Sure PR still has some weight if your going to buy a site, i think it's burnt into our brains that we need a good one, but it's not everything.

Have a great night.

[Dr-Pete]

So, keep in mind that "cheating" Page Authority isn't really very useful - we're just creating a predictive metric. We have no control over whether you actually rank. PA is a machine-learning model designed to predict the ranking ability of a page, but it's far from complete or perfect (no one number can be, although we're trying to improve it all the time).

Sub-domains are tricky animals. Sometimes, they inherit a lot of power from the root domain. Sometimes, they get fragmented and essentially act like entirely separate domains. Our PA model doesn't really account for all of that complexity. It's a best guess, ultimately. There are certainly cases, though, where a sub-domain ranks well without many unique links, solely based on the power of the root domain. That's far from guaranteed, though.