Google launched ad sitelinks back in November of 2009. Since then we learned the impact they have on organic results, at least on click throughs.
But how does Google determine which ad sitelinks to show? As you may know, advertisers can enter up to 10 sitelinks into the ad system. Google asks you enter the most important sitelinks first but Google will show only up to 4 of those links at any given time.
So how does Google decide which of four of the ten links to show?
James Carswell posted an ad sitelink experiment saying that Google basically does not pick the four based on the search query but likely based on the CTR of those links.
He said, "Doing a little testing we can see that there doesn't seem to be any relationship here." So what is it based on? He believes "it looks like Google may be testing for things like CTR of the individual sitelink entries."
He ran dozens of tests, which you can see on his blog. Did you test this? If so, let us know.
Forum discussion at Search Engine Watch Forums.
