Gregory Zura of comics publisher Fantagraphic Books writes about the imprint's new line of shelftalkers, those "little cards with a quick reading description and maybe a couple quotes of praise" you'll occasionally see hanging off the shelves, especially in chain bookstores (although staffers at indies often create their own for fave titles). Here's a half-size reproduction of one Zura created for a flagship Fantagraphics book, Love and Rockets:

That's a lot of information to process on one card which is, keep in mind, twice the size you see here—but, Zura says, the retailers tell him it works. And it makes sense that Fantagraphics would need to put out some extra info to get a potential graphic novel buyer to break down and make the purchase. But when you don't have to do quite as much convincing, you can make your talkers a lot simpler, like the National Book Foundation does (and, of course, they have the advantage of not having to deal with specific titles):

There's bound to be a happy medium somewhere between these two examples. If you're marketing books someplace, and you've got a GIF or JPG of a shelftalker you're especially proud of, show me! NOTE: Let's try to watch the file sizes, people. We much prefer things measured in Ks to those measured in MBs...