To check whether this bot is really from Google, and not some kind of user agent switcher, I drilled down on the data and here is what I found.
Googlebot appears in Google Analytics reports
First of all, as we can see below, the Googlebot is recognized as a browser (version 2.1):
Second, when we drill down to the network location report we find the following:
How does it affect the data?
If we look at the behavior of this bot, we see a very low time on site, very low pages/visit, and very high percentage of new visits. This might be due to the fact that the bot does not fetch cookies, which is essential to accurate analytics tracking. Below are some numbers:
Statistically speaking, this means that the Googlebot is an outlier, which is a data point that lies outside of the overall pattern of a distribution. It means that it can distort the numbers. In the example above, just a few visits with very low time on site and percentage of new visits can significantly decrease the overall average time on site andpercentage of new visitors, which is clearly bad for someone looking at the overall behavior of visitors.
How to exclude Googlebots from your Google Analytics data
Here is a filter that can be applied to Google Analytics profiles to exclude this Googlebot from messing with your data.
What lies ahead?
For now, we can only hope that this kind of data is not being collected by analytics packages from the back door. If it has been this might have been skewing the data quite a bit given Googlebot’s low time on site and percentage of new visits stats.
Disclosure: The data used on the screenshots above was extracted from the Web Analytics Association website. If you would like to take a look at this data, it is currently available to all members as part of the Web Analytics Championship.
Postscript: Google Analytics posted a response in the comments:
Please note that this issue requires additional investigation both in regards to Google Analytics and to how Google Search uses the Googlebot.