I just attended a writers' conference on writing for YA and I learned about "New Adult" literature, a newish market category for ages 18+. Has anyone ever heard of this before? What do you know about it?

It hasn't really taken hold. A lot of people are hoping it becomes a genre in it's own right, but for now it's still a tough sell and isn't recognized by most agents/publishers. I read an agent blog just last week that said "new adult isn't a genre" on a query critique. Some agents are giving it a shot, and hopefully more will get on board. For now though, it's in a tricky spot.
Could I have a link? I heard someone else talk of this and want to read the agent's blog!
I think "New Adult" will be the first big genre boom that's solidly e-book over print. The people in that age group are the college and grad school kids. This year's university freshmen have never lived without the Internet, so they're used to technology in a way no other incoming class is.
I think that "New Adult" may take off but at the same time, it's really the same audience that got hooked by the YA boom a few years ago. It's really just the YA readers getting older. It would be stupid to not write books appealing to these aging YA readers with college-age protagonists, with plots and stories that have themes in-between YA and adult, but at the same time . . . how many of the YA boom readers are going to make time to read a book? As someone who recently got through college, it is DAMN hard to have time for other activities especially if you're working . . . unless you want your grades to fall a letter average or so.
I think that we mostly have to wait and see on "New Adult". I think YA with 17 or 18-year-old protagonists might be more likely to break out than "New Adult", same with "adult" fiction that have protagonists in their early to mid twenties.
. . . how many of the YA boom readers are going to make time to read a book? As someone who recently got through college, it is DAMN hard to have time for other activities especially if you're working . . . unless you want your grades to fall a letter average or so.
Everyone above has basically said it right.
Ideally, "new adult" is for the college age crowd - 18-early twenties - with themes that are a little too mature/isolating to a teen (like college - something most teens can't relate to yet) but might not appeal to all "adult' readers (just as YA won't appeal to all adults). Some claim it's an "untapped" market, but, in reality, it's hard to sell, not only to publishers but to readers.
College students - generally - aren't reading much outside of required reading. They don't have time. And those who are just read adult or YA. It's not a big enough or hungry enough market to feed, which is why publishers and agents typically pass.
St. Martin's, however, is doing New Adult. A friend of mine is an editor there, and she said that they have a few upcoming titles, but they are still really selective and watching the sales carefully to see how it goes. It's still in an experimental phase. If it actually does do well and take off, the other pubs will hop on board in a heartbeat. For now, though, there's no real market.
Young Adult is popular because it's very universal. Everyone can relate to being a teenager. We all had to do it. The themes of growing up, fitting in, finding love, finding our place in the world, etc. are often shared by the collective consciousness. When you get to "college-age," that scope narrows quite a bit. Some people go immediately to adulthood. Some languish in the adolescent haze (in which case they'll probably relate more to YA). College is certainly full of unique experiences, but I don't know that the market is there or if it's universal enough to make it enough of a "thing" to warrant its own marketing group.
Okay have you seen Mean Girls?
Gretchen Weiners/ YA Authors: That's so Fetch (New Adult)!
Regina George/Agents+Publishers: Stop trying to make 'Fetch' (New Adult) happen, Gretchen (Authors), it's not going to happen!
And now I guess they're on crack.
Wait. If you haven't seen Mean Girls just ignore this post.
I disagree. I think there are a lot of universal experiences in the twenties age range that are pretty universal. I don't believe a "new adult" market should just be about college, because that's like saying The Hunger Games shouldn't be YA because it doesn't take place in high school. Separating from parents for the first time, coming to understand your own mortality, navigating living on your own for the first time, your first serious relationship, getting married--all of those have nothing to do with college but are things that usually happen in the early to mid twenties.
I agree with all of this. I think another issue with this "New Adult" marketing category is that it's really niche, specified market if you think about it for a second. It's directed at a pretty small age group (18-23ish) and usually featured something "college-aged" people can relate to. But here's the thing: a lot of people don't go to college. A lot of people don't relate to "college-age" experiences.
Young Adult is popular because it's very universal. Everyone can relate to being a teenager. We all had to do it. The themes of growing up, fitting in, finding love, finding our place in the world, etc. are often shared by the collective consciousness. When you get to "college-age," that scope narrows quite a bit. Some people go immediately to adulthood. Some languish in the adolescent haze (in which case they'll probably relate more to YA). College is certainly full of unique experiences, but I don't know that the market is there or if it's universal enough to make it enough of a "thing" to warrant its own marketing group.
It is hard to peg where your story/novel involving college age kids should be. I'm not sure it needs a new genre, but that might be because I feel people get too hung up on genre. I see a lot of wrinkled noses at the library when patrons find out that something is anywhere but the "regular fiction" section. The Curious Incident of the Dog in the Night-Time? We have that in Mystery. The Hunger Games? That's Young Adult.
I understand the marketing need for genre, at the very least, but feel almost like it's a "trap" that people get caught in. If you don't want to read about space ships fine, don't read SciFi, but also don't assume that's all SciFi is about. If you don't want to read about 20 year olds in college don't read.......yeah, what's the caveat?
New Adult is about as necessary as 'mid-life crisis lit,' 'elderly fiction' and 'end of life'.