Facebook allows us many different ways to target users with advertising. Facebook rewards advertisers for posting relevant ads. Not only money can be saved by targeting people who are interested in the product being advertised, of course, but also Facebook will charge less per impression if there are positive interactions between the user and the ad such as a click through, like, or share. There are lot of people angry about Facebook's use of personal information. Yes, but it is there and hopefully can be used in positive ways.