I just want to make it clear that I'm not trying to argue or shoot down anything you say - I feel like what I say comes off as that, but it's not what I'm trying to do. :/ Just want to make that clear.
Catcher in the Rye has a bunch of different covers since it was published, yes, but if you asked someone who has read/know the book what the cover on it was, 9 times out of 10 I can guarantee you it was one of two. One which has what I assume is a carrousel of sorts, and a city scene in the background, and just the plain cover that says Catcher in the Rye on it.
I would say the intent of a cover - beyond the given need for engagement - is to pique the interest of what the book is actually about. Even further, when it comes to Catcher in the Rye, which HAS had a huge impact on not only American culture but the youth of it's generation and even past then, you come across the issue that it's not a novel that has complete physical substance. It's based around one character primarily and his experiences, and that's where things come in to play. And that's what I'm trying to emulate: some of the most important things about the novel, or at least what has become such. I don't expect everyone to have heard of it, I don't think I said that, did I?
I would actually suggest checking out this site:
The Book Cover Archive
It has some of the best design work for book covers for the modern era - and you'll see that they aren't all "shove it in your face" imagery.
Ah, I just feel like I'm babbling on with my graphic design bullshit, I'll shut up now skjdskfh gah. I do appreciate your input though.