AdSense Laboratory

Experiment 3: Identical pages on different sites: do they pull the same AdSense ads?

On 9th September 2004 I posted a simple page on FactsAboutAdSense.com about web hosting but found that the only ads displayed were all about AdWords - not web hosting.  

See http://www.factsaboutadsense.com/webhosting.htm

I then pasted identical HTML code on my website www.CommercialReality.co.uk.

See http://www.commercialreality.co.uk/webhosting.htm

and found that after a short period when Public Service Ads were displayed, I got highly targeted web hosting ads.

The question is: what is going on? Why isn't the AdSense algorithm reacting properly to my new content on this website when it is doing so highly efficiently on Commercial Reality?

The fact is that the algorithm must use something other than only the HTML of a page to determine what ads to post.

Warning: the ads you may see on the two pages will change over time and it may be that when you look, the two sets of ads will be similar.