Because, to use an oft-quoted phrase on HN: "If you're not the customer, you're the product." If I'm not giving them money, what am I giving them? Eyeballs? Da

Because, to use an oft-quoted phrase on HN: "If you're not the customer, you're the product." If I'm not giving them money, what am I giving them? Eyeballs? Data in my emails to mine?