> I still do not understand how it makes them money,
It makes money from a pure economies of scale situation. When your marginal cost per "ad" is essentially zero, you can ship out a sufficiently large number of such ads that even the smallest percentage of recognition by the targets results in thousands or millions of return inquires/clicks/etc. I.e., if it cost $10 for 1 billion views, and only 0.0001% respond, that is 1000 responses. Effectively only costing one cent per response. If you make ten cents per response, you have made $100 on your $10 investment.
Couple that with the fact that a computer did the "work" and it is an easy money machine.
It makes money from a pure economies of scale situation. When your marginal cost per "ad" is essentially zero, you can ship out a sufficiently large number of such ads that even the smallest percentage of recognition by the targets results in thousands or millions of return inquires/clicks/etc. I.e., if it cost $10 for 1 billion views, and only 0.0001% respond, that is 1000 responses. Effectively only costing one cent per response. If you make ten cents per response, you have made $100 on your $10 investment.
Couple that with the fact that a computer did the "work" and it is an easy money machine.