Have you ever bought a Facebook ad? I have. I have talked to many, many people who have. We have spent hundreds, many have spent thousands or even more, experimenting with Facebook ads. They are worthless. Nobody ever looks at them, and nobody ever clicks on them. I just talked to someone who was trying to promote a book. He found it cost him over $100 in ads to sell one book. Moreover, as you increase your ad spending, people get used to the ads and just ignore them. So, your already low click-through rate plummets even further.
Boldfaced emphasis added by me.
That writer would have been better off spending less money to sponsor Kindle Nation Daily for one day and probably would have earned back that money the same day too. (They are apparently working on a Nook Nation Daily too, by the way. And, as usual, I have no connection to these.)