Judging by the cover

When they said, "Don't judge a book by the cover," I nodded enthusiastically. I mean, yeah, it was a wonderful feeling that, for once, there was a piece of advice which I was already following.I mean, come on, what does the cover tell you anyway? It demonstrates how good the cover artist is, not how good the author is. Even if the author did have a say in it, it only tells you how capable he is