While film is gone, digital photography is booming. Using my Facebook page to connect with other local pages, I've been amazed at just how many professional photographers there are in Perth. If you can take a nice shot, there are certainly plenty of ways to make money.
And with everyone using social media -- many of them for business and professional promotion -- a good headshot is more vital than ever.
If you run a photography business yourself then I'd imagine this would be a great niche market to focus on if you don't already. Of course social networks themselves would be an excellent way to find new clients.
But don't forget offline. You could also do local flyer drops in business and industrial areas, with promotional material focusing on the need for quality Linkedin profile shots etc. I suspect you'd have good results if you did this, since I doubt few others in this field would be promoting themselves in such a specific, targeted way.