“I heard about this self-publishing thing so I decided to try it out, wrote a novel, put it up on Amazon and it just took off.”
If only it were that easy for everyone. 
I think it is that easy if you can write a book that resonates with the readers. Too many self-pubs (like me) write stuff that is so derivative and has been done to death. The trick is finding that story that just begs to be written and doing so with such a fresh look that people will be falling all over themselves to get their hands on it.
As for the subject of this thread, I'm about halfway through his first book and while I can say it's an enjoyable read, there's not much that's ground breaking in it. You can tell the author is a big fan of the Jack Reacher novels and you could easily take the name Jack Reacher and slip it into every instance you see the name Jason King and you'd find yourself checking to see if the author is Lee Child. The only real difference is Jack is a retired military policeman and Jason is an ex-Delta Force dude.
All that being said, it is a hot genre and Matt tells a good story. I'm sure most of us would agree that that is the number one secret to this business. If either one of those is missing it will be an uphill slog every inch of the way. I'm still trying to write that story that hits on both of them. But, I have plenty of time and nothing else to do. :icon_wink: