Book arbitrage can be a great way to make extra income with Amazon FBA but it's not for everybody. While I don't have specific experience with the program you posted, I looked at the web page to see what they are all about. First, the link opened 10 identical browser tabs which is pretty suspect and feels spammy.
Their program is specifically geared to finding cheap books on Amazon that have few or no FBA sellers. You buy the books and relist them as an FBA seller at a higher price then pocket the difference.
I don't have any experience with this type of arbitrage so I can't say if it's a profitable method. If you're just starting out, I would go to places like library book sales and Goodwill to find cheap books.
There is a big movement right now for college students to find alternative sources for textbooks since they can be extremely expensive. This is an excellent opportunity to find cheap textbooks locally and sell them on Amazon. You make money and the buyer saves money vs. buying from a bookstore.
If you're considering buying this program, I would strongly recommend doing more research as there is a wealth of free information out there on book arbitrage.