There’s been a long running thread at Webmasterworld concerning a theory about a Google penalty. The penalty is called the -30 penalty.
What is it?
The minus 30 penalty is when a site drops from a previously high ranking to #31. i.e. the site dropped beneath a level where most people will see it. This appears to happen to all pages on the domain.
This theory must be difficult to prove for certain?
So, is there anything in it?
A lot of people are reporting it, and have been for some time. The problem is specific.
How do I know if I’m affected?
Do a search on the domain name. i.e. acme.com. If you’d expect to see the site at #1, but it appears at #31, chances are the penalty is in force.
If it happens to me, what can I do about it?
Tedster had a good post in the thread, which sounds most applicable: “the main thing is to fix the condition that Google doesn’t want to see in a first page result. One big factor the editorial crew looked for was many pages of mostly affiliate stuff with no “value added” for the visitor”.
The penalty, if it exists, appears to relate to a SEO footprint.
What is an SEO footprint?
Hard to say for certain, but if you run an affiliate site, containing a lot of non-unique data, you may be experiencing this effect more than most. Many non-affiliate sites are also experiencing this penalty, so it would appear the penalty also has something to do with common page and link structures. i.e. pages that don’t conform to Googles Webmaster Guidelines. In particular, duplicate content, HTTP errors, and keyword frequency. Matt Cutts has stated in a comment to a post concerning this issue – “I believe this is scoring the quality of those documents”, which doesn’t give much away at all Matt hasn’t, to my knowledge, commented on this penalty directly as yet.
It would be reasonable to assume, given the number of sites affected, that Google is applying this penalty automatically, not on a hand-reviewed, site-by-site basis.
Like all SEO theories, this one is hard to prove and pin down. But if I had to summarise all the SEO data I’ve seen, and the discussions I’ve had with people over the past year, it is this:
In 2007, domain authority is almost everything. Great content on untrusted domains goes nowhere.