Learjet said:

The problem with ghost tours is that they're boring! Ghosts don't perform on demand so the only things left are spooky stories that may be a "teensy" bit embellished and paranormal investigators that bring their own equipment ghosts with them.

I agree. About 10 years ago, for my 8th grade graduation gift (I'm a yung'in, I know) my aunt took me on a haunted bus tour of Chicago hosted by author Richard Crowe. Since I've been into this stuff for as long as I can remember, and also being a history nerd, I took in the history of the city and the folklore of the locations (Hull House, Billy Goat Tavern, Resurrection Cemetary, the site of the Eastland disaster, etc.) Lots of people on the tour complained the entire time about how they didn't see any ghosts. As you said, ghosts don't perform on demand. Also, many stops on the bus tour included restaurants, pubs, and bars, and we were encouraged to purchase something at each location.  Reputedly haunted locations definitely can benefit from a reputation of spookiness and mystery, for sure. Nonetheless, it was a fun experience, just to learn facts and historical tidbits of a place.