A friend keyed me in on a very consise article on Web Analytics for online advertising - specifically online newspaper sites; he did not have a guest post yet and gave me this article he’d like to submit instead.  I’m covering the Web Analytics article in the next couple of posts.

In specific I am focusing in this post on the concept of Unique Visitors:  There are a couple of main methods to figuring out who is a unique visitor

What is a Unique visitor?

One of the more important tracking benchmarks is the unique visitor. “Uniques,” as they are commonly referred, measure the amount of traffic a Web site receives by tracking the number of individuals who visit a site within a specific period of time. This period can vary from site to site and is determined by settings in the historical log analysis software (or, for more innovative reporting, within the implementation of advanced Web analytics services that measure real time behavior).

Unique visitors are measured by their unique IP addresses, which are similar to a fingerprint. However, an Internet server provider’s proxy server can cause many users to look like one person, and dynamic host protocols can make one visitor look like many. (As an example, a company with 1,000 employees might manage its Internet access via a single IP address. If all of those employees visited the same Web site one day, that Web site could register them as just one unique visitor visiting because all it would see is one IP address visiting 1,000 times.) An inaccurate unique visitor count can potentially skew the accuracy of Web tracking or analytics metrics.

 

That’s mainly a problem with AOL, which does a lot of internet caching.

Nielsen//NetRatings’ measurement of the top online current events and global news sites, November 2005.

Methods of determining Uniques:

Cookie Tracking, site registration, Sampling

Cookies: ….a cookie is placed within the Web browser on the user’s computer. This allows the analytic software to track all movement to the site (and throughout the site). However, if a single user accesses a site from multiple computers such as home, the office and/or a PDA the software cannot combine these visits into one visit. Other issues with cookies include the fact that they can be deleted by the user and thus will inflate a user count if the visitor returns. Or, individual users may select privacy settings within their browsers to reject the setting of cookies altogether.

Site Registration: …if you go to eBay to carry out a transaction, the eBay registration system identifies you by the cookie it placed on your computer in the past, but it also asks you to verify your login to be sure it has the right user. This way the identification of the user can be verified. The site registration form of tracking is ideal and combined with cookies provides a higher quality of site analytics

Sampling:  Nielsen//Net Ratings, tracks Web sites by using a large sample of Internet users. Nielsen counts the number of unique addresses of computer systems that are used to query a measured Web site. According to Nielsen, issues can be created by the increased instances of cookie deletion that leads to an overestimation in unique browser statistics. This also results in an underestimation of visitor frequency metrics, since repeat visitors are often recognized as first-time visitors.

Next post, Segmentation, Geographical Differences, Demographics and Psychographics.