Book cover is the first thing you notice if you are into first impressions and who is not?
And I am afraid I do judge a book by its cover, very much so. Let me give you a few random examples:-
This must be a chick book– and I will not even consider opening it.
This is obviously some murder mystery? Well now I will look to see if I can learn more about the author and maybe there is a summary of the plot.
Another mystery? But here I know something of the author ….so yes I am biased and I will probably buy the book.
Quite a smart cover and I will be interested.
A very good author , very good novel and a very good cover. I am overdoing good here
But mostly I enjoy non-fiction, history and biographies etc. and then the cover usually does not make so much difference. It usually is professionally done.