If you analyze your own traffic logs, or develop web analytics software, we have some news for you: we’re making a change to how some clicks coming from Google appear in your logs. We're writing this mostly as an industry FYI, because Google Analytics reports will not be affected by this change.
Up to now, referrers for clicks on ads for the term "flowers", for example, would be one of the following:
http://www.google.com/search?...&q=flowers&...
http://www.google.com/aclk?...&q=flowers&...
We’re adding a third possible referrer:
http://www.googleadservices.com/pagead/aclk?...&q=flowers&...&ohost=www.google.com&...
This new referrer is on a different domain named ‘www.googleadservices.com’, and has a new path of ‘/pagead/aclk’. The query is still there as the GET parameter ‘q’ and the originating host for the click is there as the GET parameter ‘ohost’. For example, if the click came from
google.ca, the new referrer format would be
http://www.googleadservices.com/pagead/aclk?...&q=flowers&...&ohost=www.google.ca&...
We’re making this change because we’re trying to improve the experience of clicking on an ad for our users. For historical reasons, Google currently uses two redirects on two different domains for many of the ads on our site. We are streamlining our infrastructure to remove one of these redirects, which brings users to ad landing pages faster, leading to a better user experience for our users and a better return on ad clicks for our advertisers.
The new referrer format ensures that advertisers will still get the relevant bits of information about a search that drove traffic to their site, but without the extra redirect.
In order to give everyone enough time to change any referrer log parsing software, we’ll be keeping the number of affected searches at a low percentage through July. In August, we’ll be increasing the number of affected queries to 100%. When we’re done, you should expect to see all three forms of the URLs.
Ali Mohammad, Ads Latency Team
