by Jim Sterne
- View article on one page
- Page 1 2
Measuring visitors, page views and actions on your Web site is finally settling down and becoming a manageable task.
As we get accustomed to the tools and the terminology, the prospect of tracking things online is no longer as frightening as it used to be. At least that was the case until November 20, 2003.
On that date, RedEye, a Web analytics vendor in London, released a little study it had done showing that everything you know is wrong. Here's what RedEye did, and what it found.
RedEye has two large clients with lots and lots of visitors: www.asda.com, the UK version of Wal-Mart, and www.willhill.com, an online gambling site (that's legal in the UK).
A majority of customers log in weekly to buy things or, even more often, to place wagers. When customers log in, you know a great deal about them. You know who they are, and through a session ID you know what they're up to. You can then compare their actions to their previous behavior.
Without the login, you have to tie that session ID to something else, typically an Internet protocol (IP) address or a cookie. We all thought that was fine.
Unfortunately, RedEye discovered that was not fine: “The results are staggering: the IP-based approach overestimated unique users by 7.6 times, whilst a cookie-based approach overestimated unique users by 2.3 times.”
How can this be?
When you log on, your Internet service provider assigns you an IP address—a number. When packets leave your computer asking for a specific URL, they contain that IP address so that the server knows where to send the page back. So far, so good.
But let's say your ISP is AOL. AOL has millions of users and large proxy servers that try to handle all that traffic. Through the magic of load balancing, they don't have to worry about everybody in St. Louis trying to access the Internet through the same machine. Instead, your request is handed over to whichever machine is not so busy, and it's then sent along to the Web site you wanted. That site then sends its page back to you via that less-busy node.
- Page 1 2
- View article on one page
