Something else to think about when it comes to free essay writing is that done for a long enough period of time, it will be something that gets around and will be something that people will expect of you. So when you start charging for your writing, you will experience a drop in business and clientele. However, you may experience this anyways because you will always want to ensure that you have a disclaimer noting that what you write is for informational purposes only.
Another thing to think about when it comes to free essay writing is that because it is free, you may want to put a limit on how much you are willing to write. The last thing you need is for somebody wanting to have you write a 12,000 page essay for free. Ideally, a small sample of your writing skills should be sufficient anywhere from 500 to 1000 words. No more as you would spend more of your time writing that getting new clients.
One other thing to think about is that ultimately, you need to be careful because the university most likely will take a rather dim view of your business and you will have issues when it comes to your own academic reputation. So you may want to avoid free essay writing altogether.