Hey, the product seems useful and interesting but IMO you need a shorter and more attractive Demo Video. Try to resume as much as you can the absolute most attractive feature of your product in the in the beginning of the video, in the store thumbnail, in the first pic, in the beginning of the description and if possible in the product’s name. I would make the vid as short and dynamic as possible and make a second video (or more) showing the details or how to use it. Also avoid too much text and long phrases in the video.
But still, being useful and well presented still isn’t guarantee that it will sell, this is unfortunately part of the business. FAB ranking algorithms aren’t public and maybe that’s to avoid exploitation.