I noticed something today that I had never realy noticed before.
When going to a page via the target keyword in Google the AdSense ads displayed are a lot more relevant than if I go direct to the page.
A perfect example of this can be seen if you visit this page,
http://www.uksmallbusinessdirectory.co.uk/dea/county-search.html
You should notice the google ads on the left of the page are not very relevant to domestic energy assessors or home information packs.
Now try visiting the same page, but this time going via this google search,
http://www.google.co.uk/search?&q=Domestic+Energy+Assessors+in+cambridgeshire
Look at the same Google ads on the left of the page, this time they are a lot more relevant
At first I thought it might be that hitting the page a 2nd time might have given google more time to adjust the ads to suit, but after much refreshing and getting to the page via other pages I have ruled this out
My only conclusion now is that Google return AdSense ads based on the keyword used to find the page
Feel free to Contact TJ with any comments.