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Why do I see different Google results than my clients? |
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Wednesday, 22 February 2006 |
Having been in this industry for as long as I have, I often forget some of the
basics. Well, it’s not that I forget, it’s just that I assume that everyone else
in the industry has the same knowledge level as I do. So when I get a “newbie”
asking a question like “Why are my Google results different than my clients” I
have to take a step back and realize that we aren’t all equal. Therefore in this
article I’m going to answer this one seemingly simple question. While it may be
simple to those of us “in the know” this isn’t always the case with others.
One of the scariest things you can do as a new SEO is talk to a client. That’s
because you are always worried that they are going to ask you a question that’s
over your head. And while you can fake your way through some questions when you
are new, there are some that just stump you. Of course even the greenest of most
SEO’s usually know more then their clients so you don’t often have to fake an
answer. Of course I would never advocate faking it. When I don’t know, I’ve
found the best thing you can say is “I don’t know, let me find out and I’ll get
back to you.” And that’s just what happened the other day. A new person came to
me and said “I had a client who saw different Google results than I did, and I
didn’t know what to tell them.” So let me give you the answer I gave him.
Google, like all the other engines, is comprised of literally tens of thousands
of servers. Each server is part of a larger cluster of computers. Each cluster
forms part of a datacenter. Each datacenter then acts as an independent branch
of Google. These datacenters are found all over the US. For the longest time
Google only had about 13 data centers that served all the results to the world.
Now the number is estimated at around 80.
While some of these data centers are used for pre-testing results (for example,
testing a new algorithm out before moving it to the main data centers) most are
used just to deal with the load that Google receives every day. These data
centers are dispersed throughout the US in geographically specific areas. They
have done this so that queries are served to the data center nearest to the
user. For example, while there are a large number of data centers on the eastern
coast, a person searching from San Francisco will likely be served their search
results from a data center near them, such as an Oregon or California data
center. It is because of the differences in these data centers that someone
searching in New York will see different results than someone in Los Angeles. It
is reasonable to think that each data center acts somewhat independently of the
others. That means that their update schedules are different as are their
crawling schedules. One can even assume that the algorithm changes which affect
the index happen at different times as well. This accounts for why there are
differences in search results. Because of Google’s perpetually updating index,
the results you see near you may be similar to results in other data centers but
ultimately different. This could be due to how the crawlers retrieve sites - a
crawler may find a site closer to it more easily and therefore add it to the
index sooner than a geographically far away crawler would find the same site.
For example, a site in Vancouver, Canada may appear in the California data
center days before the eastern data centers. Because this site would be added
to the west data center sooner, it will have an impact on the search results
returned sooner.
Consider it like the ripples you see in the water when you drop a rock into a
pond. If you drop just one rock, you see the ripples move out from where you
dropped it. However, if you drop 2 rocks close to each other and at slightly
different times you see how the ripples interact with each other when they meet.
The index changes reflect this type of interaction. One site can have a subtle
but noticeable effect on the index. Yet the effects aren’t noticed across all
data centers at the same time. We can also see the changes in the index grow
over time, so that one Vancouver site’s effect grows over time, but the effect
is different across the data centers because changes happening with other sites
also has an impact. As you can see, this is why you will see different results
across the data centers. It’s not necessarily because of one single event.
Like SEO itself, it’s a culmination of smaller events which causes the
noticeable differences.
Rob Sullivan is a SEO Consultant and Writer for
http://www.textlinkbrokers.com
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