A WebmasterWorld thread is reporting Sporadic Reports of Google Testing New Ad Layout. The new ad layout shows two ads at the top, and then four ads on the bottom, but none on the right hand panel. You can click on the image to see a full size screen capture of the new layout. Does this new ad layout suggest that Google may be adding "zoom" like features on the right hand side, similar to what Ask.com does with their search results pages? It is way to early to say.
This should create a more competitive landscape for the two top ads, if it is deployed over at Google.com Web search. Google is trying to sell the ad space to the most relevant advertiser? I have no idea if they will make this the future style but it does raise some interesting questions.
Senior Member vincevincevince theorizes;
Compare this to a typical Adsense monetised site and the cycle of changes the operator goes through over time. 1. Well defined ads which match the colour scheme and are in their 'proper' place
2. Ads moved within the 'read-line' to ensure they get seen (increase in CTR)
3. Ads in 'hot position' i.e. most important spot of page (increase in CTR)
4. More and more ads, at the top, the side, etc. (increase in CTR)
5. Ads progressively blended and made to look closer to the content (increase in CTR)
6. Reduction in number of ads to focus on high EPC ads (increase in EPC outweighing loss of CTR)
7. Experimentation with Ad Link units ("See results about 'related term')
You've got to face it, Google is the biggest Adsense monetised site there is - and many of the things that help Adsense sites get a boost apply just as much to Google herself.
Forum discussion at WebmasterWorld.