I think a setting lures people in when it has evocative names associated with it. These names might be places, occupations, people in the setting, specific powers. I remember that the first thing that intrigued me about Rifts (back before it had even hit the shelves), were the names of some of the classes... "Juicer", "Glitterboy", "Psi-Stalker". The orders of Space Marines in Warhammer 40k, and even the creatures they commonly fight against, all have names with an emotional intensity to them. The quirky OSR products that are all trying to outflavour one another with their outlandishness, each naming their locations in ways that highlight the esoterica, the psychadelia, or the grimness of their setting. Hell, even Apocalypse World did it with the short punchy names given to the various playbooks.
So, I'm thinking about the twisted new setting for our LARP. It's a fantasy post-apocalypse setting. A savage wasteland of super-tech and magic, where anything is possible if the right price is met, and as long as you can keep it hidden from the celestial bureacracy that has sworn to keep the world from becoming unbalanced. Since this is LARP, think NERF and foam weapons (yes, I know, we've been down this path before...), but from an in-game perspective think of a pan-dimensional empire, with races from numerous worlds trying to pick up the pieces as the militant order that united it has vanished without a trace. Stargate after a vanishing of the Goa'uld, the Races of Flash Gordon fighting for supremacy after the assassination of Ming the Merciless and his Imperial guards, Game of Thrones, but with guns, lightsabers, angels and demons.
To get the feel for what I'm aiming at, the evocative names will come.