A majority of apps make money in more than one way. Most of the largest apps sell your data to other companies. Marketing companies use this data all the time to target which customers would most likely buy their product or service. Apps like Facebook and SnapChat break your data down into lifestyles like adventurous or fashion lovers. They watch your interests, who you engage with and how long you engage with different types of content then place you into a category along with demographic data you entered on sign up like gender and age. Back in the day marketers used to buy email lists but now they are buying access to customer profiles. Is all of this legal? Yes, not really because its morally correct but rather the absence of laws to make it illegal. Currently the U.S. only has laws to protect children, limit unsolicited email marketing and force companies to tell the public what they do with data they collect. Its even been shown that turning of tracking doesn't promise privacy. Northern University computer scientist Guevara Noubir found that some phones can still use tracking methods even with GPS turned off. While this information isn't used to harm anyone, data hacks are becoming more and more frequent and we need to start holding companies accountable for any data theft or lose.