To AdSense publishers, if you haven’t noticed yet, Google now provides automated optimization reports via the AdSense panel. You will see it just below your earnings report in the Overview pane.
A sample of the report will look like this:
April 2007 Optimization Report
Dear Publisher,
Here is your optimization report for the month of April. After an automatic review of your sites, we think you might be able to improve your monetization using the following tips:
You may be filtering ads that monetize well on your site.
How can I fix this? Dismiss this tip.We hope these tips are helpful, and encourage you to experiment using different layouts and formats–no two sites monetize the same way!
Sincerely,
Google AdSense
I have around 100+ URLs added in my AdSense competitive filter list (a correction to Jayvee mentioning they were keywords in his iBlog3 presentation). These URLs are the ones frequently advertising on your blog and when you visit these URLs, they’re also running tons of AdSense or affiliate ads on their pages in the hopes that they could recuperate their ad spending with the ad revenue they’ll get. You filter them because they usually get the lowest bid (cost-per-click).
Though competitive ad filtering is a good move, the optimization report indicates that I might be blocking out advertisers that convert well. That means, even if their cost-per-click is low, the ads could be more relevant giving you a higher CTR to compensate for it.
The solution. Check the list again and see which ones are relevant and which ones are not. Then, de-list them and see what happens. 
Loading ...
Checking your list of blocked urls can be quite tricky. I received the same optimization tip, so being a diligent AdSense user, I double-checked my blocked urls.
Turns out, most of them were being displayed on the index of my blog where the content is fairly mixed resulting in ads being displayed but are not that relevant. Inside the posts itself though, more relevant ads are being displayed. If I remove some of the blocked urls, they push the other more relevant ads in those individual post pages since they have a lower CPC. It’s really quite tricky.
or google is simply looking out for its affiliates….
when I received that tips on the first week of April, 2007, I immediately deleted all those URLs I wish to be blocked hoping that the CTR will increase…..
Sana may isang hands-on session ng Adsense Tips and tricks and other monetization techniques.
I have also received the same report and disregarded it.
I wrote about this as well… You may be pushing up your CPC, where are you sending your users? To spammy sites? All depends on what you’re actually trying to do…