300x250 Or 336x280 - Which Adsense Unit Size Earns More Money?

I had designed most of my site around 336x280 sized Adsense boxes, but I had read that 300x250 sized boxes were sometimes better.

I found an interesting way of testing this at the following page:-

http://labnol.blogspot.com/2007/06/which-adsense-format-color-scheme-will.html

So I decided to contact Adsense Support to see if I was allowed to do this...

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Original Message Follows:
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Subject: Javascript
Date: Fri, 22 Feb 2008 03:55:55 -0800

Hello.

I just want to check with you that the following javascript is OK for
use on my web site (to randomly change between 300x250 and 336x280
Adsense adverts).

(According to a few other web sites it is) (The actual adsense code has
not been modified)..

**INTENDED JAVASCRIPT CODE FROM
ONE OF MY OWN PAGES
PROVIDED HERE**

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Hello Jordan, Thank you for your email. As per our Terms and Conditions
(https://www.google.com/adsense/terms), the ad code provided to you by
Google AdSense may not be altered in any way. Publishers may not: - Change
the way in which the ads appear - Change where ads link to - Load ads
within a new browser window - Deliver users indirectly to the URL
associated with an ad. For example, the page may not load within a frame
for your website - Alter the 'Ads by Google' label - Associate other ads
with the Google ads or the 'Ads by Google' label Thank you for your
cooperation. To uphold the quality and reputation of Google AdSense, all
publishers who apply are reviewed according to these programme policies.
You can review this and other programme policies at:
https://www.google.com/adsense/policies .

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Sean,

The code provided below does NONE of the following


- Change the way in which the ads appear - Change where ads link to - Load
ads within a new browser window - Deliver users indirectly to the URL
associated with an ad. For example, the page may not load within a frame
for your website - Alter the 'Ads by Google' label - Associate other ads
with the Google ads or the 'Ads by Google' label therefore can I assume
that the code is OK?

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Hello Jordan,

Thank you for your email.

Publishers are not permitted to modify the ad code, or to alter the
behaviour or targeting of Google ads.

For additional questions, I'd encourage you to visit the AdSense Help
Centre ( http://www.google.com/adsense_help ), our complete resource
centre for all AdSense topics. Alternatively, feel free to post your
question on the forum just for AdSense publishers: the AdSense Help Group
( http://groups.google.com/group/adsense-help ).

Sincerely,

Seán
The Google AdSense Team
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From: Jordan McClements

So you *are* saying that the code I provided is OK?

*The actual ad code on the web page is NOT modified, and the behaviour or
targeting is not changed*
.
NB - The help links provided do not help me with this query..

So I would appreciate a definitive answer if possible.

Thanks.


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Hello Jordan,

Thank you for your email.

To clarify; this implementation would violate the spirit of our policies
as it alters the behaviour of the ads. Thank you for your cooperation.

For additional questions, I'd encourage you to visit the AdSense Help
Centre ( http://www.google.com/adsense_help ), our complete resource
centre for all AdSense topics. Alternatively, feel free to post your
question on the forum just for AdSense publishers: the AdSense Help Group
( http://groups.google.com/group/adsense-help ).

Sincerely,

Seán
The Google AdSense Team

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mmmmm....

So they seem to be saying that it's not OK to implement this javascript on your site.

I suppose that strictly, you should use OpenAds to randomly rotate adsense units, or find some other way of randomly changing the ads...

At any rate, I know someone who has used a similar method on a web site that was very similar to mine and they found that there was VERY little difference between earnings in the 336x280 and the 300x250 sizes.

**Of course, as with all these things, the only way to find out for your own site is to test, and then test some more... **