Back in February 2007, Google began personalizing search results based on your search history. Google would do so, only when you were logged in. Now, Google announced they are personalizing search results for everyone, even if you are not logged in.
Previously, we only offered Personalized Search for signed-in users, and only when they had Web History enabled on their Google Accounts. What we're doing today is expanding Personalized Search so that we can provide it to signed-out users as well. This addition enables us to customize search results for you based upon 180 days of search activity linked to an anonymous cookie in your browser. It's completely separate from your Google Account and Web History (which are only available to signed-in users). You'll know when we customize results because a "View customizations" link will appear on the top right of the search results page. Clicking the link will let you see how we've customized your results and also let you turn off this type of customization.
This is big stuff for the SEO world. No matter how much we complained earlier that the personalized search results made it hard to "optimize" for, this only impacted a fraction of all Google searchers. Most people had no idea how to even log into Google. Now, Google is personalizing results by default and these same people will have no idea how to turn off personalization. So now all these users will see different results, on some level, and it does impact the SEO space - more so than when Google launched this in 2007.
SEOs, most of them, are mad. Let me quote some of the more trusted names in our forums:
So let me get this straight: to completely opt-out, you'll have to login permanently? Which moron came up with that scheme?
Wow... this is really going to overly favor websites like amazon and ebay that already have a huge reach.
The rich will get richer.
Google is using a "secret cookie" not attached to the Google.com domain to handle the Web History/Personalized Search for users who are not logged in.
The gradual impact over time will be that unaware users who click on Google search listings will reshape their search results. Unless Google develops some sort of injection to show people new (fresh) content, discovery will become more difficult for less sophisticated users.
Good news for Randy and 1dmf's Google Rank Extractor. And also for moving people further and further away from traditional rank checking as a measure of success.
Google are there to find ways to best meet the needs of the searcher. As much as we want them to be, they are not there to meet our SEO needs.
The possible impact to all is staggering.
This just feels so very wrong-headed that the mind boggles! As I often explain to IT staff, NOT EVERYTHING THAT CAN BE PROGRAMMED SHOULD BE PROGRAMMED.
Sounds like an attempt at a product improvement. SEOs may or may not like it, but the real question is whether Joe Searcher likes it. If Joe does, Google will remain one big step ahead of its competitors. If Personalized Search turns out to be Google's answer to Windows Vista, Google will need to bring back Google XP or leapfrog to Google 7.
Danny Sullivan has an excellent write up about this at Search Engine Land, he doesn't seem to touch on the SEO view of this.
Honestly, if this makes Google more relevant for their searchers - all power to them. I am not going to say I know what is better for the average searcher. They can quickly figure this out after days and decide to keep it, turn it down, or off completely. SEOs will adapt, like they always do - we are a strong and smart bunch - I am not worried.