none y.

For starters, many idiotic reviews on here are for books, not the company, bookbub. Most ebooks are trash, which is why they sell them to suckers for cheap or free. Sometimes they are marginally good, and free only to get you to read the other author's books.
The great authors spend years researching their books, months of editing, formatting, and reviewing their book. As a reward, bookbub expects the author's hard work to be given away free or cheap. Anything for free does not have value.
In addition, the ebook retailers take the hard work of the author's reviewing and formatting their book into perfection and trash it all, cramming spacing together into a non-stop robotic reading. In other words, you get what you pay for.