I'm curious how this website is doing this..If you look at the screenshot, you'll notice they have a "Search. Save. Buy." adsense banner which lets people search for airfare. No matter how many times I refresh or check in other browsers, this ad always seams to come up. Is it just coincidence this is the ad showing up, or is it possible to specify this kind of ad on your site?
My experience with AdSense you pick and chose which ads you would like to use and the placement of these ads. So they obviously chose that ad and placement for a reason.
Placement targeting does NOT work that way. Publishers can use filters, but not select specific adverts. Advertisers can.
In my case it was a 728x90 ad: But you can't really search through the ad. You have to click on the ad to go to some page. You see that blinking cursor in the search box simply because it's a gif animation.