Publisher Rocket?

I am always looking for different ways to market my books. I have hopefully improved my targeting on Amazon, but I am not sure. I have changed the seven targets that you set up when publishing your book twice now. I read and listen to a lot of different people, and now I am contemplating buying Publisher Rocket to help me find more successful targets. Does anyone have an opinion on Publisher Rocket? If so, I would love to hear from you!