Uneven distribution of ads

I am clueless ...

[onlineleben]

I have one adgroup with 3 ads and the distribution of ads is switched to "Rotate: Show ads more evenly"
This selection let me assume that the 3 ads get their equal share of the pageimpressions, but the results I see for yesterday (Tuesday is already closed in my timezone) are 26.9%, 29.9% and 43.3%.
Why is the distribution not so even as expected (33.3% for each ad)?
Is this setting only valid for ads on google itself or does it include the Search Network?

Additonal facts:
Budget is high enough, Campaign is set to run in Google and Search Network, Pageimpressions just below 100 for yesterday, last changes to the ads were done on monday morning.

Thanks for any advice.

[Kings on steeds]

Could be that the changes to the advert havent been proofed yet, so your not on search for two of your ads.

Thanks only thing i can think of.

Alan

[netmeg]

I had this happen, and I sent a question to support to ask them. I'm not allowed to quote the email here, but paraphrasing, was told that since the introduction of Quality Score, this feature doesn't work quite the same way as it did before - your ads are supposedly entered into the *auction* on an even rotation, but because there are other factors being taken into account now, it doesn't mean they'll SHOW evenly. Kinda messes up split A/B testing, don't it?

[KaloVast]

It does mess up split testing a bit but it also seems easier to identify how newly implemented key phrases in ads influence your click through rate. I've wondered about this in the past, as some of my ads seemed to be showing more often than others. But in many cases the click through rate was also higher, so i found it easier to test for the most successful ads. I think it also means, in a roundabout sort of way, that you can create multiple ads in the same ad group and focus those ads on different keywords. whichever ad is most relevant to the keyword should show.

Any thoughts?