• by August 11, 2000

Advertisers place a lot of emphasis on the number of visitors a site receives each month. Media Metrix and NetRatings reports are the most widely recognized sources of this data, but since these companies cannot possibly track every site viewed by every web user, they monitor panels of about 50,000 people and then project that data across all web-enabled individuals.

Because of this, one of last month's issues of The Industry Standard reported that traffic figures from the leading web measurement firms can be "flawed and wildly inconsistent."

Here's an example: Earlier this year, AltaVista's traffic numbers were growing steadily each month. In January, Media Metrix reported that the site cracked the top 10 and jumped to the 9th most visited site on the web.

But when the February Media Metrix numbers were released, AltaVista's traffic was reported to have dropped by over a million visitors and fell out of the top 10. Incidentally, AltaVista's internal records indicated that the site had a great month and gained 7% more traffic.

A recent article by Brian Cavoli, about.com's Online Advertising guide, states that interestingly enough, there has not been a significant amount of criticism about these measurement inconsistencies because people seem to accept them as growing pains.

So here's the real question (and a makeshift questionnaire): how much stock do you put into web activity numbers and whose numbers do you trust more - the websites themselves or the monitoring firms? As we watch the total number of active web visitors slip slightly into the dog days of August (that's according to NetRatings), are there more important factors to consider when deciding where to run your banners?