I'm doing a similar test at the moment. One week in so far, nothing solid yet. My theory is everyone is smart priced to a degree, that smartpricing is account based, is driven by poor performing pages and messes up earnings on the best performing pages.

Hope the one page you left ads on isn't the home page.

I'm through with performing tests at this time. I've removed ads from poor performing sections for months at a time, not for a few days or a week, in order to get the best data and it's made no difference.

Changing the ad unit sizes and adding more ad units have made a difference.

Beyond that, the way I see it, it's a mix of keywords used to access your site (a variable somewhat under your control but subject to query-demand variable that is out of your control) and advertiser competition for those keywords used to access your site.

One of my popular and important sites is currently down 30% of where I like to see it, and down about 60% from the high levels it hits at certain points in the year. That's all normal for that site.

No, the site isn't really set up that way. I'm 100% sure what page gets the most AdSense action and so that's all I needed to know. So far, it's looking like this is the way to go for my site - fewer pages with AdSense, but better paying. Earnings still way off from the highs of yesteryear (oh but to be able to turn back the AdSense clock to 2005!)

That probably makes your site visitors happy.

I think that's the big problem for my niche, not enough advertisers. I've been with AdSense since 2004 and have seen advertisers come and go. A few years back, it seemed there were a lot more advertisers jockeying for position on my sites. Nowadays, the advertiser pool seems much smaller and the clicks pay a lot less. That's why I removed AdSense from most of my pages yesterday, to try to maximize the CPC for the few advertisers I still have.

[edited by: Play_Bach at 9:25 pm (utc) on June 24, 2008]

[edited by: Play_Bach at 3:29 am (utc) on June 25, 2008]