Looking at all the swag I took home from LTUE, I'm going to examine what worked on me, and what didn't.
1. Business cards
Business cards are the most traditional and understood way to network. It's got exactly everything it needs and nothing else. This works great if the person who takes your card is actually interested in you already. Otherwise it'll just got lost in a stack.
A few things make a business card stand out to me. The first is excellent visuals. The inkpageant.com card works really well on me because it's very simple, and it has a pleasing, well-designed visual. It's just the logo to their website. They could cram that card with all the services their website offers, big-name bloggers who use it, etc., but they decide to hang everything on their simple, effective logo. Easy to pull this card out of a stack.
The second thing is novelty. In particular, Eric James Stone's business card actually has a short story on the back of it.
That's pretty awesome. It gives people an excuse to want your business card outside of just networking, and offers meaningful content. Note that I said "meaningful." Throwing a Sudoku or tic-tac-toe grid on the back of your card may be different, but it's not meaningful if it doesn't relate at all to what skills you're marketing. Eric James Stone's card works really well because it illustrates exactly what he does: writing short stories.
I don't know how I feel about bookmarks. First of all, who uses them anymore? More and more people read electronically. Of course, the kind of people you'll usually give these to are probably big enough readers that they could ostensibly use a bookmark for something. But there are so many bookmarks out there, I don't know that anybody really needs another one.
My second qualm with bookmarks is that they only really expose themselves while your target audience is already invested in reading something else. "Yo dawg, I heard you like text so I put some text in your text so you can read while you read." So if you're going to do a bookmark, I would aim for the more visual kind, like the "Upside Down" bookmark you see above.
Bookmarks at least set your material apart from standard mini-fliers, handouts, or business cards. And they're clearly linked, utility-wise, to the product you're promoting.
I'm sure there's a better term for these middling things, that are usually about a quarter of a piece of paper in size. They can be cheap to produce, but if you look at that stack, some of them stand out a lot more than the others. Those are the ones who pay for better physical material (glossier) and ink so they can show off their visuals.
The three there on the bottom are for a series of books, but it was the illustrator who gave them to me. I told him I was an aspiring writer and he showed me some examples of his work in case I wanted a cover artist. It wasn't just yet another paper to stuff into my bag, but an actual tool for his pitch. Again, if the point is marketing your content, it's useful to have something that can show it.
4. Free content
People always jump at free stuff. Even if the content is only somewhat interesting, hey, it's free, right? The only problem with that is that you're giving away content for free. As Tracy Hickman said so cleverly, "free books are worth every penny." People may wonder why it's free and subconsciously decide the quality is low.
My advice would be to only give things away for free that you can afford to give away. Don't rely entirely upon all your free content to quadruple the sales of your priced content. Brandon Sanderson put his latest book up for free online, but that was only after being picked to write THE WHEEL OF TIME and he wanted something he could point WoTers to so they'd have more faith in him (and also buy his other books.)
I liked how Dr. Carlisle just put a stack of his papers in the Dealer's Room instead of waiting for people to ask for his expertise. He just cut out the middle part of the process. If he was willing to give that out for free, he might as well just literally give it out for free, right?
Posters are more expensive to make, but super effective, in my opinion. People want cool posters to hang up and look at. If you're confident in the visual you can produce, as far as selling your product's tone and quality, a poster may be your best bet. This was a poster for the Writers of the Future contest. They're not just trying to get people to buy their anthology, but submit to it as well. Writers are confident in their own text, but what a contest has to sell is their ability to promote your work once you've won. They do it with this strong genre visual. Every writer thinks, "Man, I would love for my book/story to have a cover like that." It suggests the contest's level of quality and professionalism.
If the image is cool enough to put on your wall, you're going to subconsciously be traveling to the world of that image all the time, whenever you look at it. That's why they do movie posters.
I saw an awesome poster in my friend's basement the other day, showing off some cool steampunk world. I asked them what it was from, and they said "I don't know, some graphic novel. I just picked up the poster because it looked cool."
Looking cool always works.
Feel free to share examples of effective promotional material that worked on you.