The first law of selling is to know your customer. This simple maxim has made Google into the world’s largest purveyor of advertisements, bringing in more ad revenue this year than all the world’s newspapers combined. What makes Google so valuable to advertisers is that it knows more about their customers — that is to say, about you — than anyone else.
Where does Google get this knowledge? Simple. It watches most everything you do and say online — reads your email (paying special attention to purchase confirmations), peers over your shoulder while you browse, knows what you watch on YouTube, and — by tracking your devices — even knows where you are at this very moment. Then it assembles all these bits of information into a constantly updated profile that tells advertisers when, where and what you may hanker to buy.
Details may be found at https://goo.gl/EFAOkV.
Do you think this is a privacy problem? Yeah, me too.