"If you’re not paying for it, you’re not the customer; you’re the product being sold." This statement is complete nonesense and I do not understand why it keep

"If you’re not paying for it, you’re not the customer; you’re the product being sold." This statement is complete nonesense and I do not understand why it keeps appearing everywhere. You are almost always paying for apps and services, and you are never the product being sold. Sometimes you pay with cash, sometimes you pay with ad impressions. But you always pay and you are always the customer that needs to be satisfied. Facebook is not free. You pay for it with your willingness to have Facebook show you ads. Ad impressions are as good as money for Google, because they can exchange them for USD. Google Search/Gmail/Maps are the products. And Google has to make them as good as they can. Otherwise you, the customer, will stop paying for them.