Why most of Google Services are free.

If you are not being charged for a product, you are the product.

Google gives you a lot of free things. Those free things are Google’s payment to you.
What is Google? If you say “a tech company” or “a search engine company,” you are wrong. Google is an advertising company.
Google makes its money by selling you. You are the product. Google sells information about you to advertisers. The information they sell is way more detailed and complete than you think it is.
Everything you do with Google’s “free” stuff is recorded and analysed to learn more about you. Every email you send or receive through Gmail is scanned for keywords. Google knows what you like, what you hate, what you're afraid of, what you buy, and what political views you hold. They can deduce from your pattern of usage what hours you work and how far from home your workplace is. They know if you're cheating on your partner. The information they collect would make an old-school KGB agent green with envy.
Their business model is selling access to you based on this information to others. Not to government agencies or private investigators; that's chump change. The real money is selling access based on this information to people who want to sell you things.
Apple sells computers. Google sells you. When you deal with Apple, you are the customer. When you deal with Google, you are the product; Google’s advertising buyers are the customer.
A lot of folks have pointed out that Google does not sell personal files on its users. This is mostly true; what they're selling is access to you based on your information.
I say “mostly true” because Google does sometimes sell aggregate search data that has been “anonymized” (stripped of personally identifiable information). However, the information Google (and others) gather is so deep and so detailed that it turns out to be very easy to figure out which individuals the “anonymised” data belong to.



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