Photo source: Blue Fountain Media on flickr.

Over the years, I have often heard the question "My Google Analytics numbers don't match my web analytics numbers. Which one is correct?" Well, the answer to that question is that both are correct. But how can that be possible?

It’s All About the Data Gathering Process

The explanation is that they use completely different methods for gathering analytics information, since they are intended to be used by different audiences for different purposes. Google Analytics is most commonly used by the Marketing team, who tracks metrics like page views, unique visitors, traffic sources, pages per visit and bounce rate. Web analytics, on the other hand, are used by the IT team, who are responsible for server, bandwidth and resource utilization.

Call it the CMO vs. CIO divide!

How Google Analytics Gathers Data

Google Analytics uses a client-side technique for gathering analytics. When an HTML page is sent your browser, it contains some JavaScript code that is then executed by the browser, sending information to the Google Analytics service.

Google Analytics is very effective at tracking page views and unique visitors, but only for those web assets that can embed JavaScript within their payload and are processed by a web browser. So, essentially only web pages. Google Analytics does not track analytics for resources such as images, and videos. For marketing purposes, Google Analytics are especially relevant because they represent engagement with real visitors to your site.

How Web Analytics Gathers Data

Conversely, web analytics use server-side techniques for gathering analytics. When a web server receives a request for a web asset, it records this information in a repository. Since it is responsible for processing every type of request, it tracks information for every type of web asset, including pages, images, videos, etc. This makes web analytics very useful for IT professionals, as it allows them to analyze how various requests are being handled and more easily identify errors, configuration issues, and performance problems.

One difference in these data gathering techniques is related to non-human web requests. Although you usually only think of engagement with real live visitors on your website, there are also other types of automated visitors known as robots and spiders which interact with your website on a regular basis.

A good example of this is GoogleBot, which regularly visits your site and indexes the content so that people can find you in the Google search engine. When a robot or spider visits your site, it does not process an HTML page the same way as a standard web browser.

Since a search engine’s primary focus is on content and links, it is not interested in the visual rendering or functionality of the page. So it removes all scripts from the page, including HTML tags and JavaScript. This means that requests from automated visitors will not be recorded in Google Analytics, as the JavaScript will not be executed. However, requests from robots and spiders are recorded in web analytics. This can lead to some very significant discrepancies if you try to compare the two sets of numbers, as your web analytics will always be significantly greater, sometimes even 10x or more.

Photo source: User ares64 on flickr.

A Look at Related Services

Confusion can also arise from other types of web services, as it really depends on how those services are implemented and integrated into your website. The value that you get from most services is usually based on some form of analytics, but since some rely on client-side techniques to track analytics and others rely on server-side techniques, it makes it really difficult to correlate the results.

For example, if you post some content on a third party service that contains a link to your website, you will be interested in knowing how many times that link gets followed. However, it is not always obvious if the third party service is using client-side or server-side techniques, if they are including or excluding automated visitors, or if they have some proprietary algorithm based on IP address or time span to prevent abuse of their service. All of these factors can lead to a different tabulation of results.

Conclusion

So going back to the original question, it should be now quite understandable why Google Analytics does not match your web analytics. When it comes to analytics, you really need to understand how they are being tracked and what they represent before you can use them effectively in your business. It really comes down to choosing the right tool for your intended purpose and remaining consistent over time, so that you can get the most value.

Related Reading

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