Well, this is bizarre. Minutes ago Paul Berry, CTO of the Huffington Post, tweeted that “google analytics chrome 6 bug is going to be big news”. After a little digging, we think he may be right: Chrome 6 (and the more recent Chrome 7, which is still in beta) is causing issues with Google Analytics, causing traffic data to be seriously skewed for visitors using Chrome’s browser. The number of Unique Visitors reported by Analytics is jumping up, but the average number of pages viewed by each user is dropping off a cliff. Update: See below, Google says that there was an issue, but that it has been fixed in the most recent Chrome update.
Here’s how one site administrator describes the issue on a Google support forum:
With the release of Chrome 6 we’ve seen a huge jump in Unique Visitors and Visits, which would show that the issue (some sort of Cookie “dropping”/overwriting) happens during the visits as opposed to in between the visits. This also pushes the Avg. Pageviews per Visit down, so we know that those really aren’t just extra visits that we receive. Looking at the Avg. Pageviews per Visit by each of the version (5, 6, 7), I can see Chrome 5 has a healthy ~20 pageviews per visit average, while 6 & 7 have around 3 pageviews per visit, which points to session (cookies) being cut down all the time.
It looks like this has been going on for weeks now, too. We’ve just delved into our own Google Analytics logs and are also seeing similarly odd behavior from Chrome browsers starting at the beginning of September. Chrome 6′s release date with September 2.
We’ve reached out to Google for more information. Update: Google has given us this statement.