At first I was unhappy when Google started doing this new customization stuff. Below is what I cut and pasted from my FireFox browser.
Search customization details: internet marketing companies
When possible, Google will customize your search results based on location and/or recent search activity. Additionally, when you're signed in to your Google Account, you may see even more relevant, useful results based on your web history.
The following information was used to improve your search results for internet marketing companies:
You or someone else recently searched for seo company using this browser. Learn more
However I am reconsidering my initial dislike of this, now I am not sure. Please consider the following facts. In my industry location does not generally matter, I can help a client in London, Detroit, or Los Angeles all the same. So if I was #1 on a search for Internet marketing companies in the USA, I would be against customization based on location because it would harm the amount of traffic I receive, if however I was #7 with location customization turned off and #1 with geographic (localization) customization turned on, than this would be good for me. I would only be #1 with it turned on in a limited geographic area, however it would still bring my business more traffic because being #7 with localization turned off would bring me little or no traffic.
Currently I do not know if this will bring my business more traffic or less, and it also may vary based on several factors, and offer different results where for some webmasters this will be a good thing and for some webmasters this will be a bad thing.
If anyone has any useful and good data regarding this please email it to me at: firstname.lastname@example.org and let me know if I may publish what you send to me.
I plan on working on this more and trying to figure out if this is a good thing or not. So please check back in a few weeks as this article hopefully will be updated by then.
Also sometimes when I write these articles I smile because most people that read them, e.g the average web site owner newbie trying to learn about search engine optimization and Internet marketing have absolutely know idea what I am talking about, it takes a more experienced webmaster to understand these issues. Also I am not sure why Google is so convinced this localization stuff is such a good thing. Clearly it is not good in all cases, and I am not even sure if it is good even in the majority of cases. Furthermore I think Google should make what I am discussing in this article more clear to the average Joe, and make it easier to turn on and off.