In a sense, they are suckers. Plus, as another story on HN suggested, their abandonment of advertising you things you don't need right now(but you may find you want later in life) proves counterproductive. A heck of a lot of things advertised to me on Facebook are things I already searched for and either purchased or already decided wasn't worth buying. I don't believe that modern internet ads are as valuable as the industry seems to think, which may be a sign of an impending bubble burst.
But still, when you advertise X to people who searched for X' (or even X itself), you can see the conversion rates of those ads, right? And you should be able to measure if that setup is profitable or not.
