UPDATE @ 14.35 GMT: From Google directly: this test was conducted on less than one percent of advertisers where there was a favicon associated with the display URL of ads. It was not possible to opt in or out of the trial.
Further confirmation that advertisers had display favicons shown in paid search results without their knowledge or implied consent. Interesting, eh?
UPDATE @ 13.07 GMT: Google have confirmed that there's "no chance" (their words) for advertisers to be included if they wish. Further credence to the earlier opinion that advertisers might not have known about the search favicon in the first place.
UPDATE @ 11.18 GMT: As helpful as our account manager is, he has to toe the party line. He did however give some insight into how Google got the favicons in the first place - the images are taken from the favicon associated with the display or destination URL, and advertisers are not actively involved in uploading them (which would make sense as the images are stored on Gstatic).
This is mighty insightful, even if it wasn't meant to be. It means that Google is testing these favicons solely with advertisers they've chosen, and it is likely that those advertisers might not have been fully aware that they were being picked for favicon testing. The official response is (as usual) "Google is constantly experimenting with new features and visual treatments to improve the user experience and usefulness of our ads."
I wonder if search results will be whitewashed and published; if the beta does come out, we'll be able to gauge the effectiveness of favicons in paid search straight out of the gates.
Original Post Continues Below...
After noticing Google displaying favicons in paid search results, I asked around on Twitter to see if anyone else was having luck replicating the search results. Shimon Schwartz tweeted me to say that favicons in search results aren't exactly new - Yandex has been using them for at least three years.
The only difference with Yandex is that the favicons do not appear in the paid search results on the right; they take up space along the natural search results on the left. Barry Schwartz
noticed a Yandex-style result in Google back in January, but it seemed to be a short burst with no further sightings in natural search.
Fast forward to this morning, and I've spoken to our Google account manager in London. He confirms that it was a limited test and that he was surprised that I even saw it as it was contained to such a small number of users. Basically, it's a trial to see how it goes; advertisers were chosen by Google with no way to actually sign up to the beta. I would stack it up to grossly unfair, but as the AM said - it's so limited to a very few number of advertisers and users, it probably won't make a heckuva lot of difference.
I'm trying to find out more about the limited alpha test, and I'll post a response as soon as I have further information.