An upcoming change to Google.com search referrals; Google Analytics unaffected

First, just a heads-up that if you don't analyze your own traffic logs, use Urchin web analytics software, or develop web analytics software, you probably don't need to read this post. We're writing this for the most geeky among us, because Google Analytics will not be affected by this information. On the other hand, we do want to let you know about some changes to Google search that are coming down the pike, before you start seeing (potentially) alarming headlines.

Starting this week, you may start seeing a new referring URL format for visitors coming from Google search result pages. Up to now, the usual referrer for clicks on search results for the term "flowers", for example, would be something like this:

http://www.google.com/search?hl=en&q=flowers&btnG=Google+Search

Now you will start seeing some referrer strings that look like this:

http://www.google.com/url?sa=t&source=web&ct=res&cd=7&url=http%3A%2F%2Fwww.example.com%2Fmypage.htm&ei=0SjdSa-1N5O8M_qW8dQN&rct=j&q=flowers&usg=AFQjCNHJXSUh7Vw7oubPaO3tZOzz-F-u_w&sig2=X8uCFh6IoPtnwmvGMULQfw

The key difference between these two urls is that instead of "/search?" the URL contains a "/url?". If you run your own analyses, be sure that you do not depend on the "/search?" portion of the URL to determine if a visit started with an organic search click. Google Analytics does not depend on the "/search?" string in the referrer, so users of Google Analytics will not notice a difference in their reports, but other analytics packages may need to adapt to this change in our referrer string to maintain accurate reports.

The new referrer URLs will initially only occur in a small percentage of searches. You should expect to see old and new forms of the URLs as this change gradually rolls out.

If you are using UTM-based tracking with Urchin Software, you'll want to stay tuned for a software update that we'll be making available soon. If you are using IP-Useragent based tracking with Urchin, you won't be affected since this form of tracking can successfully process both current and new referral strings.

Posted by Brett Crosby, Google Analytics Team