What is a good book cover?

This is a book that I recently read and that I really liked. The book is about the life of Amir and how he went back to Afghanistan during a time of war to save Hassan's son. I think the book cover does capture the gloomy and sad mood of Afghanistan in times of war; however I do not think that it is a good book cover. While the book does show the bad conditions of Afghanistan, the entire book is about Amir's life and his relationship with Hassan and his regrets, but the cover did not show any of that. This is a really good book, however, the cover is not successful in portraying the story or draw people's attention.

I liked these five book covers because each one has something different about them. I have not read any of these five books, but the their cover drew me in. The first book is titled crime, but there's a huge lollipop on the cover, which made me look at it again. The Emily Dickinson book cover is very simple, but I really liked the image. I thought it was very unique and fit well with the title. The third cover was interesting because I this author's book all have the black frame which almost made the book cover look like a photo rather than a book cover, and the same goes with the last two, the arrangement of the texts were very interesting. So I guessed what caught my attention in these covers are the placement of the text, the image and their relation to the title of the book.