Our focus was only for tabletop games, but I had 2 LARPs (owbn vampire and werewolf) ask for space. I like both styles of play, so we decided to give it a shot and rent extra space. The LARP pretty much had their members there, but not a lot of sign ups from the tabletop crowd. I was kinda surprised that there really wasn't any crossover.
I'm not surprised. OWBN is designed for you to have a long-standing character. There'd be an expectation that the folks playing in the game had established characters, and likely established relationships. That can be a daunting social barrier for a new player, and probably seen as not worth the effort for a one-shot.
If you want to encourage crossover, your games (both tabletop and live-action) should probably be self-contained and stand alone, without folks bringing in established characters, or requiring the player to have much world or rules knowledge beforehand.
Education and example may be the only way to sell it. People need to know what a LARP is and isn't as well as what to expect from that experience. I'm still trying to figure out how to do this for my own convention.
I think folks get into live-action games largely the same way as they get into tabletop - someone they know invites, educates, and brings them in. If you lack the established social connection, trying to encourage them to do something new when they already have a room full of stuff they already like can be difficult.
One possibility - get a couple of "horde-style" live action games. This construction is like most TV shows - there are a handful of central cast characters, and then a horde of extras. The cast play the same characters for the entire game, and the extras come in, play a role for ten minutes or half an hour or whatever, and then walk out again. Maybe they pick up a new horde character, or maybe they decide to wander off and do something else.
I've had some luck with occasionally wandering over to a room of tabletop players and saying, "Hey, folks! I need four people to play badass bikers causing trouble in a diner. It'll take like ten minutes. Any volunteers?" They get a really short taste of live-action play, with no real commitment to spend four or six hours at it.