advertisers have to pay to have their puppy ads served to a certain audience, men age 15 to 54 living in tucson who make $50,000 a year. there are a lot of ways for advertisers to target ads, all based on extensive estate that facebook gathers from users. with technology called facebook pixel it can track what sites a user visits and get better ad targeting. and you don't even need to be online for your behavior to be tracked. a vendor can buy your purchasing data from third parties, and that can include things like ael the purchases made when you use a store loyalty card. if you have the same e-mail address or phone number linked to that card and your facebook profile, the data can be linked and used to fine-tune ads that you see online. all this results in the personalized results we see in searches and ads on facebook and it can vary in small ways or big ways from other users. while the process varies across the internet, the principle is