I sold maybe two copies of my novel Replica in July, while charging a measly $4.99. We dropped the price to $0.00 a couple of days ago. The result? 800 downloads on Amazon (I don’t have any data on Barnes & Noble).
I don’t have any great insight to offer. People like free stuff. I just hope that some of those 800 folks read the book, like it, and leave me a nice review. And, maybe, buy one of my other fine novels.