Quoted from TheCreature:

It's not a worn out theme. Horror pins have traditionally been amongst the most popular recurring themes in pinball. Horror comedy too. Elvira may be an 80's icon, but a GERMAN company just released the Elvira Mistress of the Dark move on Blu-Ray for the first time. It made all of the major horror news sites and movie/blu sites. People are paying the extra money to import them to the US. It's a big deal.
Beyond that, she's still a staple at Halloween and Comic-con style events. Knott's Scary Farm keeps bringing her back by popular demand. So there's multiple generations of fans. Her brand is still strong.
Now let's talk business: what's the age group that has the disposable income that are entering or supporting the pinball resurgence right now? It's her demographic of fans. What about kids who grew up playing Scared Stiff and Pinball Monsters? They're that demo now. If they loved those games, and there's a good chance they did, they might not want to drop $10k to get a nice restored Scared Stiff, but they might pop $5-6k for the chance to own a NIB Elvira pin. Add in Color DMD and new tech? It's a real tempter.
I was speaking with a new friend the other day who learned I was into pinball. He told me without prodding that he had joined Pinside just to see how hard it would be and how much it would cost to get a Scared Stiff... his favorite game. He's 40. Correct demographic. He said something about the game's theme and simple design and rules being accessible and easy to grasp making for quick fun. I've heard many others say the same thing.
My wife's favorite two pins and the ones she plays all the time either virtually or on location are Scared Stiff and Theatre of Magic. For whatever reason (probably the fact that she's empowered) she has a strong female appeal. Mix that with her 'classy chassis' and you've got a pin that's likely to do well on location with both sexes.
Last thought on this: Elvira may keep coming back, but the two previous pins she's had have been very different from each other. At this point, Elvira's new pin could be classic horror based, gothic based, slasher style based, 'new' horror based, or a satire of anything-- music, other pinball tropes, politics, or even (gasp!) her age. "Elvira: Over The Hills?" anyone?
I just got my Rob Zombie delivered. I have a feeling Elvira 3 is next. If the art is good and it shoots well? I'm in!