For me covers are absolutely crucial to selling a book. They should be as captivating as possible. Also, the cover should rappresent at least a small part of the book's plot, so I understand the choice to include an internal illustration of the book on the cover. The title and font are also very important to attract attention. The illustration and title must combine perfectly to create a functional cover. I think if one of them is weak, the book will probably go unnoticed. When I go to the bookstore, I often hunt for books that I can use as study material for work, so I choose something that can serve as a reference for me. But I often find books that catch my attention unexpectedly, for the story or a different style. Covers with bright colors and an interesting composition definitely catch my attention.