Did you know the Northstar Nerd is actually four people, or five, or six people?! As crazy as that may seem, I just received an answer back from Google tech support on an anomaly I had noticed on both historical WebTrends, and current Google Analytics data. Here is the situation, my company has around 120k employees. Web metrics data from both systems stated that in a 30 day period over 220,000 unique visitors had visited our internal employee portal.
There were two ways I could interpret this data:
- Wow ... what great usage stats!
- Eh gad ... this can't be correct ... we only have 120,000 employees!
I chose option #2, as I doubted that my company had recently hired 100K employees. My other action was to contact Google and provide them the data from both systems, and explain the scenario.
Earlier today I received a nice answer back from Google. After much internal discussion, they felt my data was correct, but I had to remember what the term "unique visitors" actually indicated. Almost all web anlaytics services (Google, Omniture, WebTrends, etc) use tracking cookies. Cookies track unique browsers, not unique people or vistors.
Let's consider my own example. I have four computers: an engineering work station, a laptop, an iPad and an Android smartphone. On each system I use mutliple browsers for various technical reasons (Atomic for iPad, Chrome, Firefox, Internet Explorer, and Safari). Thus, since cookies are measuring unique browsers (i.e. cookies) during a 30 day period, I might represent 12 unique users in a web analytics report. Remember, when I use a different browser on a different computer, I will be assigned a new unique tracking cookies for that computer and browser.
While most users might not use as many computers and browsers as the NorthstarNerd, it is not unusual for a typical user to have more than one browser, and visit your site from both home and work. Thus, most people would at least score a "four" on the unique visitor / cookie count ... I suspect more.
The moral to the story is be careful if you report "unique visitor" data. Your users might not be as unique as you thought. Finally, Google also told me that based upon my data they are working on trying to determine a way to account for this issue.