Don't Judge a Book by Its Cover. Really?

So the other day I heard someone say "don't judge a book by its cover" and I thought, um actually, I do that all the time. In the literal sense of course. In no way does this post apply to people.

Being the nerd that I am, I looked it up, and according to Wikipedia: "The English idiom don't judge a book by its cover is a metaphorical phrase that means one shouldn't prejudge the worth or value of something by its outward appearance alone."

Ok well, yes and no. I agree with this, except not when it comes to books. I think the cover of a book is meant to tell you as much about the book as it possibly can at first glance. It should make you pick up the book and think, hmm, looks interesting. Then you could proceed to flip through, read the back cover, skip to the end and read that (barbarians), or whatever else you do to decide if a book is worth your time.

I guess that's where the alone part comes at the end of the Wikipedia quote. We look at the cover AND THEN we look at a couple other things before deciding. But still, the cover of the book plays a huge role, and I think the biggest reason for that is YOU know what YOU like to read, and you use the cover to weed through what you don't like. Maybe one of the easiest clues the cover gives me is a pretty obvious understanding of the book's genre. Let's try an example. As a fantasy reader, which of these three book covers would be most appealing to me?

(Smile by Raina Telgemeir)

(Burden's Edge by Sever Bronny)

(The Wind and the Sea by Marsha Canham)

Now I've never read any of these three books, but come on, it's pretty obvious what they're going to be about. Wanna know how I can tell? BY LOOKING AT THE COVERS! Smile is probably going to be a realistic fiction about teenagers overcoming relationship problems. Burden's Edge is probably about a kick butt sorcerer in a medieval type kingdom. And The Wind and the Sea is probably about some scandalous piratey drama. Do you see what I'm saying here? It would be so obvious to me as a fantasy reader that Burden's Edge is something I'd like and the others are way outside of what I'm looking for. (No offense to these particular books or their authors by the way. Like I said, I haven't read them. I literally just pulled them off Google to use as an example.)

You're probably thinking, but those books are in completely different genres, that's why their covers are so different. And you're right. I'm not arguing with that logic. But I will say "cover judging" works for weeding out things you like and things you don't, even WITHIN a specific genre. My friend and I are a good example. We both love fantasy, but she tends to like fantasy books like this:

(The Siren by Keira Cass)

And I tend to like fantasy books like this:

(Bloodwitch by Susan Dennard)

Again, I haven't read either of these, but can you see what I'm trying to show? If I picked up The Siren, I'd probably shrug and put it back. My friend would do the same to Bloodwitch. Is that "judging" a book by its cover? Or is it just knowing what we enjoy and choosing accordingly?

I will say that this method isn't foolproof for choosing the best books. For example, my friend and I both love this book:

(Mistborn by Brandon Sanderson)

And this book:

(The Shadow Queen by C. J. Redwine)

In both cases, we're crossing the line into books we don't normally pick up, but we enjoy them anyway. So you can't REFUSE to read something simply because the cover doesn't match with what you usually like. I'm just saying it could be a good way to narrow down a whole library shelf of books into a handful you have a good chance of enjoying.

So tell me what you guys think. Is it ok to judge an ACTUAL book by its cover? Does anyone else use this method, or am I just super closeminded when it comes to picking books? Let me know in the comments!