BusinessWeek has a good article discussing web metrics and it seems based on this article that all methods for measuring web traffic are flawed in some way. The article mentions some of the current ways to measure web traffic are Alexa, Nielsen//NetRatings, comScore and HitWise. According to the article at least in one case, Yahoo! has seen an increase in traffic for one of its sites while one of the web measurement companies has seen a decrease. Still I believe one or two instances of inaccurate measurements does not a trend make but there are other factors in the article which are worth understanding.
For example in a Web 2.0 world it is challenging to accurately measure a web site’s reach because the concept of page views goes away. In other words, Web 2.0/Ajax pages don’t refresh like Web 1.0 pages – they just update the portion of the page that needs refreshing.
For advertisers who use page views as a way to measure advertising effectiveness, this leads to an obvious dilemma. How does a web 2.0 site get credit for all the traffic they bring. If someone spends an hour on a web 2.0 site this will count as a single page view. On a web 1.0 site this same visitor would rack up dozens or hundreds of page views per hour.
Other challenges are widgets which are applets installed on other websites such as MySpace which give some program functionality without requiring a person to visit the original website supplying the program. There is currently no way to give credit to a website who has widgets sprinkled around the net.
Other challenges are RSS readers which also allow a user to be consuming web content without the associated page views.
In short there is currently no really good way to measure a site’s effectiveness in a comparative way. Widgets, RSS/XML and AJAX are making it tougher than ever to determine exactly how much traffic a site is getting and moreover as these new technologies become more popular, existing web measurement techniques become less effective.
You think you have a better solution to this problem and just wish you had the resources to go and start a new traffic monitoring company? Here is some good news… George Zachary of Charles River Ventures says "If someone came up with something better, I’d fund them."