An internal link is less value than an external link.
I'm not saying that per se, a link in terms of PR will transfer X
amount of PR no matter where it is, so in this sense internal/external
are the same. But, if you have created that pages PR from your current
PR to expect it to do the same as a link from an external site is just
misunderstanding PR since it's taken PR from your other pages, so they
will no longer result in the same sized boost.
It's an easy mistake to make, you have a load of good PR internal
pages (or pages you own on any site) that are created by your linking,
not from links from others sites and so are confused as to why those
PR5 (for example) links to a new site/page doesn't result in the sort
of boost you might get from 50+ similar PR pages from other sites
(sites you don't own).
If you have 100,000 PR points (making this up as I go along, so don't
take the number too seriously) on your entire site and through
internal/external linking (so all links) 30,000 of those points end up
at the home page.
If you now add 1000 new pages (all linking to the home page) and that
adds say 1000 PR points to the site, the site now has 101,000 PR
points. But if you have linked to the new pages from existing pages
(from the same site) less of the overall PR points will end up at the
home page (the new pages have used some of the PR points, much more
than they created). So the home page might be 25,000 PR points.
So basically you have added 1000 new links to your home page, but
because those links have drained PR from your other pages through
linking, your home pages gets less PR. Although PR per se isn't the
main factor in SERPs the anchor text of links is very important and
one factor must be the PR of the page linking. So the anchor text from
a PR7 link will be worth more than a PR6 link (all other things being
equal).
So if you reduced the number of PR points to the home page from 30,000
to 25,000 this must mean the anchor text of the links must now be
worth less, so you would anticipate a fall in the SERPs.
It's not an obvious conclusion, but adding new pages to a site or
creating a new site and linking to it from your current sites will
make getting current SERPs harder if you aren't very careful how you
link it altogether.
What is the key difference between internal and external?
domains? sub-domains?
"not owned by you" = not on the same domain.
No means not owned by you personally, a site you don't control or if
you do control it the links are new to the network of sites you are
considering.
So if you have two domains A and B and currently every page of both
sites links to the home page of both sites. You add 10,000 pages to
site A or B and link all to both home pages. If the 10,000 pages are
linked into the navigation system of the above sites as I described in
an example earlier then those pages will NOT give the home pages a
boost, but will likely result in a drop in current SERPs.
Same situation but this time you add 10,000 pages to another site,
site C which is a site currently not linked to sites A or B (this bit
is very important). You link the new pages to the home pages of sites
A and B and those 10,000 pages are added to the navigation system of
site C (so they have links which gives them PR). In this situation
sites A and B gain PR and a boost from the 10,000 links at the expense
of other pages on site C (and anything else site C links to).
You can "own" site C, but as long as it's not part of the network you
are working on right now, if you add links from it your other sites
gain.
Generally though what I'm thinking about is links from sites you don't
have any connection with, so if you got a PR5 link from a DMOZ cat
this would give your site a boost and would be a link from a page not
owned by you.
Of note, reciprocal links are a difficult one as it depends on the PR
of both linking pages and how many links from each page. If you setup
a reciprocal link with a lower PR page or the number of links are
wildly different your site in general will loose out on PR. That's not
to say a lower PR reciprocal link can't help your SERPs, since PR
isn't the all and end all of SEO and even if you do loose out, since
it's a reciprocal link you get some of the PR back, so it's not as bad
in terms of PR as some of the examples above.
Isn't that your whole reason to use sub-domains, since google will
see each as a separate site,
Yes, that's one of the reasons, but not for the reasons you are
thinking.
and so count cross linking as external
links, not internal.
No. I use sub domains because they are free, easy to setup and to
Google are no different to real domains.
If you understand how PR works you will see Google does not have to
worry about webmasters creating loads of sub domains and linking them
together since it only works if you get the sub domains links in their
own right. If you use your current pages to feed the new pages your
current SERPs will likely suffer.
That's not to say adding lots of new high content pages to your site
is a bad thing, you will gain new SERPs and so it's well worth it over
all.
I've added over 60,000 pages to my literature sites, I knew before
designing the site layout etc... adding so many pages so quickly will
make obtaining the harder SERPs harder. The literature sites are a
very, very, very long term project and I know a couple of years from
now they will have many more incoming links from external sources
(from sites I don't own) than they have now, so there will be enough
PR/links to obtain the harder SERPs. Basically right now I'm not
interested in specific SERPs for the literature sites. If all I cared
about was specific SERPs for the sites I'd not of created so many
pages so quickly.
Also the best design would of been as few pages as possible per book
so as not to spread the PR so much. If I have a 250 page book (I have
a lot of books with over 250 pages) most of those pages will not
result in any search engine traffic, so in terms of links/PR it's
wasting good links and PR for no SEO gain.
That's my essay for today
)
David
