I can say with reasonable confidence that a large number of teachers, at all levels, probably have no idea that services such as ours exist.
I'd very strongly disagree with that. If they didn't know these kinds of services existed, they wouldn't require students to submit their work to turnitin. That practice evolved precisely because essay companies used to do a ton of business reselling pre-written essays and it basically created the market for original custom essays. Before the Internet age, pre-written essays were mostly retyped from the hardcopy essay collections maintained by fraternities, for which a service such as turnitin would have been useless. In my view, the popularity of turnitin among professors suggests very strongly that they are
very aware that this industry exists. It's not effective against custom-written original essays, but they know that it is still extremely effective against the product that dominated this industry until roughly 2007 and, in their minds, at least it reduces cheating because it forces their students to go with a much more expensive option.
I know that having a model paper in front of them can really help the kind of student who benefits from having an example to follow.
What percentage of your customers do you think really use your work only as model for their own work rather than submitting it for a grade?