Indeed - compared to nothing it is very good
The other problem is there is no filtering available. So you can't tell what is a genuinely new book from an author, versus what is just a reissue from their back catalog, or a different edition etc. So when my favourite author has 4 upcoming books, turns out it is only one being released in a range of formats. That is where being via a plugin could be handy, to filter out all the "cruft" by comparing with books in your database and only tell you about *genuinely* new books...