Comments on: Google Analytics Accuracy – Comparing Google Analytics, Yahoo Web Analytics and Nielsen SiteCensus

By: Yulia

Yulia — Mon, 05 Apr 2010 18:17:29 +0000

Hi Brian,

Here from Occam’s Razor.

Thanks again for the link. This is a very useful comparison chart.

Yulia

By: Brian Clifton

Brian Clifton — Fri, 26 Mar 2010 14:17:41 +0000

Jose – even if the page tags could theoretically execute as exactly the same time there will aways be differences in metrics. The following whitepaper (updated just last week!) details pretty much everything related to accuracy. Its also vendor agnostic:

http://www.advanced-web-metrics.com/understanding-accuracy

By: Brian Clifton

Brian Clifton — Fri, 26 Mar 2010 14:16:28 +0000

Dee: This sounds very much like an implementation issue. The following whitepaper (updated just last week!) details pretty much everything related to accuracy. Its also vendor agnostic:

http://www.advanced-web-metrics.com/understanding-accuracy

By: Dee

Dee — Thu, 25 Mar 2010 10:49:50 +0000

I’m posting here because of an experience we are having at the moment, causing our company to investigate the accuracy of the various analytical tools.

Our group has a number of international divisions, however a UK product company has an Enterprise Risk Management product it has been promoting online.

It purchased banner ads with a major site that carries much of the key news in the sector, along with sector specific jobs etc, and has a reported monthly unique user base in 5 figures.

During the first month of the campaign we received only 6 hits from this site – which really suprised us, as our Ad campaign on Google PPC was light years ahead of this.

We contacted the ad site vendor and addressed this with him, explaining that we were suprised to only have 6 hits recored on Google Analytics coming through from his site. He expressed suprise as his data shows almost 300 click throughs on the banner to us.

As you can see this is confusing. We’re not expecting thousands and millions of clicks as ERM software is not that interesting and we accept that not that many people want risk software, but the core issue here is how to explain the variance between the Ad Sites figures and ours?

The click through rate they are reporting is 40-50 times what we are actually capturing on Google Analytics. The above article talks about a 10-20% variance, but we are waaay outside of this.

Is there any reasonable explanation any of you might have for this that we might be overlooking?

By: Jose

Jose — Wed, 28 Jan 2009 19:58:53 +0000

Brian: The ranges of discrepancy between both tools are similar than the one’s you specified for Yahoo Web Analytics. Also the group of pages considered for the evaluation are verified to have both tracking codes.

Considering that GA code is included just right after SiteCatalyst code, simple logic will tell us that for a high traffic website, GA should report less number of PVs. However it is consistently the opposite.

That’s why I was wondering which can the reason behind this discrepancy, and confirm if differences between the tools themselves can be the cause.

Thanks,

Jose