Jim Sterne at Stone Temple Consulting on May 7, 2007 published a 2007 interim report detailing accuracy and reporting differences / discrepancies of a number of industry standard website analytics software packages.

Although there are undoubtedly discrepancies in the information the various software reports to you, Jim Sterne makes the very valid point “If your yardstick measures 39 inches instead of 36 inches, it’s still great to have a measurement tool”, basically your software even if not 100% accurate provides a benchmark for your statistics as your software will always lack accuracy by the same percentage; so day by day you will know if you have comparatively gained or lost traffic.

The report is very interesting and in depth, well worth a read if you are interested in website analytics. The full report with the final results is due out in July of 2007, which will undoubtedly provide a lot of insight into the website analytics software on review.