Everywhere I look I see a ghost tour on offer. It's amazing - hard to imagine that there are that many ghosts hanging around to entertain the tourists. It's still a fact that the dead outnumber the living but with China's 2009 population of 1,338+ million and India's 1,156+ million that might soon be changed. If, that is, we didn't live in a world where 24 thousand children die each day.
Even so, most people who die do not hang around in perpetual haunt-mode. I won't upset anyone's beliefs here except to say that most pass on to other things.
Which is why, I guess, that many ghost tours are more like theatrical entertainment than real paranormal experiences. It's pretty hard to run a ghost tour when few (if any) of your clients are going to experience anything beyond a cold spot of a a bunch of orbs on their digital snaps, so I guess you have to improvise a little. Perhaps more emphasis should be placed on 'experiencing' locations rather than promising encounters with the paranormal.
It's pretty hard to argue that they are fraudulent however. To do that would require legal recognition of paranormal activity - something that doesn't occur (at least not in Australia).
None of this means, though, that there are not tours where you do have a good chance of encountering 'things that go bump in the night'. There are locations which have some form of other-worldly influence of one type or another. There are a number of types of manifestation and despite the hype, those who are sensitive to such things can find some tours very rewarding.
At the end of the day, it's important to learn as much as possible about the tour before you take it. Check out forums, see what others have thought about the experience. This is often a good indication of the real nature of the tour. Is it show or is it real? Is it both? They are not mutually exclusive - just because the host is wearing Victorian clothes does not mean that you won't meet up with a ghost! Nor does it mean you will, though.
So are they worth the money? Some are, some are not - unless you are just after a bit of fun. And there's nothing wrong with that. Just be clear about what you are interested in and seek the experience of others who have been on the tours (not just the tour operators!) to see if it is likely to match your expectations. At the end of the day, if the tour delivers what you want then it's worth the money. Whether that's a show or a real paranormal encounter - that's a different story.