We previously talked about how “private browsing” modes aren’t really private. They still let websites track you across the net. But why all this tracking? Let’s take the prime example–Google. If you ask most people what Google’s business is they will say “search,” but Google actually makes a lot of its money from serving ads on other sites. Put simply, Google isn’t a search company, they’re an advertising company. Princeton’s WebTAP privacy project recently found that Google’s trackers are installed on 75% of the top million internet websites. The next closest is Facebook at 25%! (See Figure 3 in Section 5.1 for details.)
Google sells ads not only on their search engine, but also on over 2.2 million other websites and over 1 million apps. Every time you visit one of these sites or apps, Google is storing that information and using it to target ads at you. That’s why you may have seen ads tracking you across the net!
If you want to stop websites from re-marketing to you, you’ll need to install a free tool like Privacy Badger which blocks trackers. Stop ad stalking today!