By Melissa J. Luther
An HTTP cookie—usually just called a cookie—stores useful information about your Web site’s visitors. Cookies do not collect personal information, but they can recognize individual visitors. Most analytics programs use some combination of tracking cookies and IP addresses to track visitors’ activities.
What is a Cookie
A cookie is a small text file that your Web site’s analytics program places on a visitor’s computer, allowing your Web site to communicate with your visitor’s browser. A first-time visitor’s browser sends a page request without an accompanying cookie. In response, your server generates a new cookie and sends it to the browser along with the requested page. As the visitor navigates your site, the browser returns that cookie to your server along with each new page request. This is how your Web site and your visitors’ browsers “talk” with each other. This conversation is stored in the cookie.
Each visitor is associated with a unique cookie, so you can differentiate unique and returning visitors as well as see where they go within your site.
There are two types of cookies:
- Session cookies: These cookies, also called transient cookies, only last for as long as a visitor is on your site. They help improve visitors’ experiences on the site by keeping them temporarily logged in or remembering shopping cart items. The cookies disappear from the visitors’ computers when they leave, but the data is stored in your analytics program.
- Persistent cookies: These cookies, sometimes called user cookies, continue to “live” on your visitors’ computers after they leave your Web site. You can set the expiration date for these months or even years into the future in order to recognize returning visitors. Sites that keep you permanently logged in use persistent cookies.
Tracking Customers with Cookies
Cookies can track visitors from the moment they arrive until they leave, including where they came from (PPC ad, search engine or direct link). The cookies and the requested URLs, along with the date and time of each request, are stored as a log file on your server. All requests associated with a particular cookie came from the same visitor, and by viewing the log file, you can see how a visitor navigated through your site.
Persistent cookies also allow you to see when visitors come back to buy or browse more, as well as whether they purchased on a first visit or a later one.
Potential Issues with Cookies
Tracking visitors with cookies is not perfect, and the two most common problems are:
- People clear cookies. Returning visitors who have cleared their cookies since their last visit will register as new visitors.
- People deny cookies. These visits will not register at all.
Most people clear cookies rarely if ever, and even fewer actually deny cookies. The impact of these actions on your tracking will depend on how tech-savvy your audience is.
Even considering their imperfections, cookies provide valuable insight into your Web site’s visitors and their preferences.
About the Author
Melissa J. Luther, owner and founder of LookSee Information Solutions LLC, helps small businesses create and maintain a strong online presence. She takes a multi-channel approach, with a well-optimized Web site as the center of an online presence that includes content creation, PPC advertising, linking, and social media as appropriate.