I have a book coming out in January called Macbeth's Niece. I don't know where my idea for the story came from, but most writers don't, I suppose. We don't choose to write about a particular subject. A plot forms in your head and you can't stop thinking about it until you write it down.
Anyway, Macbeth's Niece sold, so now I'm asked all the time, "What's the name of your book?" The first thing I noticed is that "Macbeth's Niece" is very hard to get across verbally and often requires severeal repetitions per listener. If I could do it again I'd choose something crisp, like Clan Macbeth. That can even be said with a Scottish burr, which I'm sure would add a few sales.
The other disheartening thing is that when people hear the title, their faces often freeze in that, "Oh, God, she's going to ask me something about Shakespeare" look. Now the book has very little to do with Macbeth, and hardly anything to do with the Bard. It's a romance, and my protagonist happens to be the king's niece, which gets her kidnapped and spies, witches, outlaws...etc. etc. I counted on the fact that everyone's heard of Macbeth via high school, and that does work for some (especially writers, who love the title). But the average man/woman on the street has a residual fear of the very name "Macbeth." Some try to dredge up a factoid from their memories to show me they get it. I've heard, "Did he really have a niece?" from one guy and another person answered for me, "Of course not, he's a fictional character." (Hmm.) Another conversation went, "Isn't he the guy with the mother?" (Well, yes, I suppose he had one. Most do.) Often the subject of conversation is swifty changed: "So how about those Tigers?"
The point? I'm not sure. We write what we write, with no idea how it's going to play in Peoria (or in Petoskey, which is closer to home). A title may appeal to people because of familiarity, but it may cause in some a shudder and a rejection due to previous experience. That's too bad. They will never know how cool girl my hero Tessa is, no matter who her uncle was.