Being the search engine with the majority of the user share in Europe, I am sure the majority of you would have either personally or indirectly (as it has been reported to you) experienced the “Domain diversity” problem.
What is Domain diversity problem?
I bet that an image is worth more than 1000 words. Problem is that after the new update announced by Matt Cutts, the query results I found in the past appear effectively to offer a better user experience. So, in order for you to understand, have a look at this site where [another] SEO discussed about the domain diversity problem.
Did you notice something strange in this SERP? Yes, that loads of results belonging to the same domain was very odd and useless.
A back-dated problem
The domain crowding was a problem that in theory Google solved back in April 2012 with the release of a new project called Horde. However, SEOers around the world and perhaps users all know the truth and counting the complaints I received may become a new hobby that I don’t really want to engage with.
The situation appears to have changed now, and a recent update released last Friday should have fixed the situation. This is really good news and I wish to further discuss with you if you find some oddities.
In short it destroys domain diversity in search results and as a consequence, the search result quality is reduced.