In principle, yes. You may have to look at a larger sample of data to get a good measure of the results.
I recently applied this technique and found good results. I originally was trial having two 336x280 rectangle AdSense units side by side above my articles which was obviously above the fold, and found that I was getting a very good CTR but my earnings per clicks (EPC) was fairly average. So I reworked my layout and made it so I only had one large rectangle at the top of the article and placed one at the bottom. I also placed four generic images beside the large rectangles to draw a little more attention to the ads. I found that my EPC probably went up about 25% for the top AdSense unit, but my CTR went down by about 10% for that unit, but it was an overall earnings gain, and one that I was very happy with. Plus I was also earning an addition 10 - 20% from the AdSense unit at the bottom that I wasn't previously earning. I think the key thing to remember is that Google will place the highest earning ads in the first AdSense unit as it appears in your SOURCE CODE not as it appears on the page. So you need to make sure that your highest CTR unit is the one that appears first in your source code. That is the reason why you can increase your EPC - because you are removing the "cheap" ad options for visitors to click. I applied this template change over 20 article pages that received about 3,000 unique visitors a day, and those results were based over about a period of a week. So I think that the results are based over a large enough sample to assume that they are fairly accurate.
It's not against the TOS as long as the images are not relevant. http://adsense.blogspot.com/2006/12/ad-and-image-placement-policy.html The way I have set up my "images" next my ads is to create a small blue circle and to place them near to my ads... Not to deceived users or anything but to just try and get more users to actually read the ads. If my visitors thought that my ads were somehow related to a small blue circle with a slight bevel and 1px black border... well I don't think Google would hold me responsible for their complete stupidity. Plus I have already had my site looked over by a representative of the The Google AdSense Optimization Team, and was given the all clear.
actually, google uses shapes next to ads as an example of what *not* to do: http://adsense.blogspot.com/2006/12/ad-and-image-placement-policy.html
But if you look closely to the ads that they are displaying the shapes are "relevant" to the ads that are being displayed as the additional image is designed to "deceive" rather than draw attention.
The policy clarification by Adsense on December 18 is quite clear - images next to ads are against TOS. You will be banned if they discover you are doing it.
Despite what you guys have said, I was confident that my methods are within the Google AdSense TOS, so I sort the opinion of the Google AdSense team to give the final word on my my integration of "images" next to my AdSense ads, and well I thought I'd just update you guys on what Google themselves have said: http://forums.digitalpoint.com/showthread.php?p=2076389
This is the point... if your second ad (as appears in source code) is getting a much better CTR than the first, then removing the first might increase the revenue.
I'm kinda confused now. Some says that the one which load first, some say the first one at the source code. Burta, can you take a screenshot of your ads with a small blue circle? I don't think it's against AdSense TOS as you describe. It's just like unordered list dots isn't it?
Well the one that appears in the source code first should be the first to load. As for the screenshot I posted one in this post: http://forums.digitalpoint.com/showthread.php?p=2076389
this explains why suddenly my click value dropped to half and CTR doubled. just remembered that I added another link unit on the site , I wonder what should I do now? should I remove the link unit or leave it there?