As a B2B marketer you may get asked about the cookies that Google Analytics uses.
Perhaps your management is concerned about liabilities or regulations.
Or you have customers with questions about privacy.
Or you may simply have colleagues who are confused about the difference between first-party and third-party cookies.
We’re going to focus on the simplest configuration of Google Analytics which is tracking a website.
How Google Analytics collects information
When a visitor’s browser requests a page on your site, your web server sends the page to the browser. As the browser reads through your web page it encounters the Google Analytics Tracking Code. The GATC then begins to execute. It identifies attributes of the visitor and the browser like the number of visits to the site, where the visitor came from, the operating system in use, and the name of the web browser.
After collecting this data, the GATC creates (or updates if they already exist) some small text files called cookies on your visitor’s computer. It then stores the information it has collected in these cookies. Once the GATC has stored the relevant information, it then sends the information about the Pageview to the Google Analytics server. GA processes the information about your visitor (and all your other visitors) and creates your reports.
As your visitor goes from page to page on your site, the Google Analytics Tracking Code on each requested page updates the cookies with new information about your visitor’s session.
[Note: For more on this topic, see this how Google Analytics collects, processes, and displays data in this excerpt from Cutroni’s Google Analytics book. Or this article from CardinalPath on really understanding Google Analytics.
The purpose of each of the GA cookies
Why does GA need more than one cookie to store your information?
Because it wants to track not only the activities of your visitor in that session, it wants to remember if your visitor returns to your site.
Let’s look more closely at the specific cookies that GA uses.
What about first-party versus third-party cookies?
Google Analytics only uses first-party cookies. Only GA can set these cookies or retrieve the cookie data, a security feature that is built into the web browser. The information in the GA cookies can include an anonymous visitor ID for personalized information such as a welcome-back message to a return visitor. But GA does not store any personally identifiable information in your visitors’ cookies.
GA does not use third party cookies. These cookies are associated with embedded content or advertisements that visitors have not requested directly. The website domains that run the advertisements place cookies on the visitor’s browser without the visitor’s permission and often without their knowledge.
You may be in an industry that is strongly regulated or whose customers are very security conscious and cannot set cookies in your visitors’ web browsers. If you can’t gather information about visits and visitors, does it even make sense to implement Google Analytics?
Even without cookies you can still use GA to collect useful information. Kaushik in a primer On Web Analytics visitor tracking cookies written in 2008 points out that you can still learn a lot about “Top Visited Pages, Revenue, Referring Websites (URL’s), Search Engine Keywords and on and on and on.”
What about cookie deletion rates?
Another cookie-related issue is the question of cookie deletion rates. You may be concerned that high deletion rates are skewing your data. The first thing to remember is that web analytics are not a strict accounting system. They are a way to see trends and to conduct experiments that make it easier for your buyers to find you and your online content. As long as the cookie deletion rates are consistent over time and across your buyer segments, then you will still get a lot of value from the trends you observe.
But, you insist, what are they? Kaushik (in the same article mentioned above) makes the anecdotal observation that he consistently sees 3-5% deletion rates for first-party cookies and 20-25% for third-party cookies.
There you have it, a crash course on Google Analytics cookies. Cookies are a way for GA to collect visitor information for your website over the course of a session and multiple visits. They do not contain personally identifiable information nor are they shared with any other web domain. They are not harmful to your visitor’s computer. They can be deleted at any time.