Both Jason and Frater Barrabbas have written some excellent post about the route of the professional magician. Frater Barrabbas notes that the professional magician route isn't necessarily for every occultist and that doing a job he loves is actually good for him in a variety of ways. I can appreciate his perspective, and its one reason I have a professional business that is not oriented toward magic. Jason also makes a good point, that you shouldn't go into magic with a focus on making money off of it, at least not initially, and that ideally it is a calling.
I agree with both of them and I probably fall in between the two of them. I don't offer to do spells for people, although I am happy to give readings and do spiritual coaching. I write books and help to publish other people's books on magic (including a few from Frater Barrabbas) and recently I've started offering a correspondence course (with more planned down the line!). That's likely the extent of what I'll do a professional magician. I don't want to cast spells for people because I feel they should solve their own problems using their own skills. But I also don't want to work at a corporate job. I think it's a dead end, unless you get into the right discipline and frankly the disciplines I've seen that are the right fits are ones that would bore me to tears. Plus I love being self-employed because I'm able to work on my own projects, and help people in the way I've been called to help them.
I do have another business and with both that business and Magical Experiments, I'm making some inroads, which are making my life better as a result, but its taken a lot of work. And in my opinion to be a successful professional magician you have to also be successful as a self-employed person. Not everyone is cut out to be self-employed, especially because you need to actively work on your business, as well as within it. And if its a service business, which professional magic would be, expect it to take even more work. Selling a product is easier than selling a service.
I think its good that magic is becoming more of a professional activity, in the sense that it makes it that much more acceptable in mainstream society. Such inroads are always useful, but its also important to continue to focus on magic as a spiritual path. The main focus of my work is exploration of magic as a spiritual and practical process for improving life, and that focus informs my work as a professional magician.