Yesterday I reported that one of the many Yahoo announcements were that Yahoo was going to test running Google ads on Yahoo Search USA.
According to a Search Engine Watch Forums thread, the Google ads are now live on Yahoo. Note, if you don't want your Google ads to show on Yahoo, you need to opt your ads out on showing on third party search providers. In any event, some advertisers are noticing that their Google ads are showing up in Yahoo sponsored results.
As expected, the ads don't appear as AdSense ads - they simply look like Yahoo ads. SEW moderator explains, "Yahoo seems to be configured as a Google Search Partner, not as an AdSense publisher." In addition, he adds, "Initially (i.e. earlier today) I was only seeing my ad a small percent of the time (i.e. Yahoo was only including it on a fraction of the SRPs for a given search), but now I'm seeing my ad 100% of the time." But the ad is only showing when he stopped showing his native Yahoo ad, i.e. the Google ad won't show for him until he tells Yahoo to stop showing his Yahoo ad.
His conclusion so far?
The net effect is like a pooled ad resource, where Google and Yahoo have pooled ads to run on Yahoo (and maybe soon on both engines?)
Note, this is supposedly only suppose to impact 3% of Yahoo's search ads in the US. It is also suppose to run only for about two weeks.
Forum discussion at Search Engine Watch Forums.