Note to querying authors:
I'm newly 22 and I still proudly read and love YA novels. And, considering my newness to the industry and late birthday, I'm about the youngest person you're going to address with this letter: everyone who would read it after me is older than me and also reads and loves YA novels (it's why they publish them, after all). Saying that your novel is "probably geared more towards young adults, but written so that adults can enjoy it too" is insulting to us AND says that you don't know what you're talking about. It implies either that we publish/represent books we don't enjoy and are just in it for the money (of which there is so much, of course), or that we're somehow wrong for liking them despite being adults. We don't take well to either of those suggestions, partly because they are surprisingly common misconceptions about the industry. Plus, it's a raging display of ignorance. In recent years (since Harry Potter, mostly, but even more in the last 2-3 years), YA novels have really hit it big thanks largely to these adults who read and love them, and every author & editor & fan is writing blogs about how adults love YA novels, too (see things like
Forever Young Adult and
Mundie Moms). And it's for what they are that we love them, not because they fit into some category that you consider "worthy" of adults. The YA books that become hugely popular don't do so because they're more sophisticated (um, TWILIGHT) but because they offer readers something they don't get elsewhere. The fact that you even thought this worth mentioning in your query letter says to me that you don't know anything about the YA community, that you don't pay attention to the discussion or even read the books. So why, I wonder, are you writing a so-called YA novel? And why should I trust that you know anything about young adults? Don't try to write a crossover novel (or market yours as though it is): the people into whose hands you're putting your book know about YA novels and the adults who love them. Trust them.
PS: It's also insulting to the kids who read these books and to other authors, since you seem to think most YA books are stupid. This is frustrating and yet ANOTHER reason I don't trust you as a YA author, but is less of an issue because these people aren't going to read your query. But you really should try to avoid insulting anyone in it, however accidentally. It's only polite.
Disclaimer: I am an intern. I know nothing. I just have opinions, a great love of YA, and lots & lots of query letters in my head.