I was wondering, why are there no google ads on the swine flu search term: http://www.google.com/search?hl=en&q=swine+flu&btnG=Google+Search&aq=f&oq= http://www

I was wondering, why are there no google ads on the swine flu search term: http://www.google.com/search?hl=en&q=swine+flu&btnG=Google+Search&aq=f&oq= http://www.google.com/search?hl=en&q=swine+flu&btnG=... is this not a reliable way to tell if there are ads or not? or is it that not enough ads have been bought?