Odds of Hanging On
While there isn't a whole lot of competition out there (save for Bob Larson, who's leading that pack with his website, DVDs, and seminars), there is some.
Exorcism experienced a big boom in the 1970s and is now having a sort of...renaissance period. More and more people are coming out as believers in possession and demonic invasion, and are seeking help and solace from their spiritual leaders.
It might be wise to specialize in certain aspects of exorcism in order to stay current and abreast of trends. Perhaps childhood demonic possession is where your heart leads you. Or maybe it's poltergeists hanging out in older houses, known as "infestations." Or perhaps you feel a calling to the sort of diabolic activity known as "oppression" which lies somewhere in between total possession and infestation.
If you want to stay in the business, you've got to keep up on the trends, the way people think and the many (often ingenious) ways in which the devil worms his wicked self into people's souls. And be careful you don't get involved in a career-ending death.
Take the case of Anneliese Michel, a German girl who was diagnosed as possessed but who also suffered from epilepsy and depression. After dozens of exorcisms failed, she quit eating, and eventually died of starvation. Her parents and the two priests who'd tried to exorcise her were found guilty of negligent manslaughter a couple of years later. Guess the devil won that round, huh?