Most people understand how Google Adsense works. Google Adsense is a money-making program for website owners that allows them to place code on their websites that has been provided by Google in order to display adverts. When someone clicks on one of the adverts, Google and the website owner take a share of the money charged to the Advertiser, who has uploaded the ads via Google Adwords (also known as PPC).
Now – Google determines what adverts go where by indexing the content of the website in question, so that if your website is about dogs, you’ll see adverts relating to dogs. You might see ads for dog baskets, dog insurance and other related dog products, but what you shouldn’t see is ads for mountain bikes from Halfords.
That’s what I saw recently on a website that had nothing to do with mountain bikes. The odd placement of ads was dismissed as simply Google placing random adverts until it had enough time to index the website in question in order to place relevant ads, yet something seemed odd as I was actually thinking of buying a mountain bike at the time. Was it chance, or did Google know?
Have we entered some Minority Report situation where Google now knows what you’re thinking of buying, and offers you relevant adverts in order to complete the sale?
Suspicions were confirmed when reading about the semi finals for Britain’s Got Talent on the metro.co.uk website where, once again, the same mountain bike adverts from Halfords appeared.
Source : http://www.stuckon.co.uk/adsense-indexing-your-bookmarks-2345.html