The best thing you can do is provide a better service than your competitors and it won't matter.
You can't really force competition to stay out of the market, and if you could, you'd soon be in for a heap of anti-trust and anti-monopoly lawsuits, which you probably don't want either.
The reality is, competition justifies your whole existence. The fact that there is a whole category of businesses trying to do it means that (a) you have a viable idea, and (b) that the potential customer base will feel like "this is a thing that people are doing these days, so I should find a business that's doing it and get on board."
Granted, it means you'll have to have competitive pricing, and fight for customer's loyalty, but it is things like these that keep your business moving forward.
I'd suggest that instead of looking for how to prevent competition from popping up, that you focus on how to best attract potential customers' attention, provide the best service you can, and do it for a price that respects the customer's wallet.
I know it sounds cliche, but if you stick with learning the tried and true principles of running a good business, you'll have more success than if you focus on making sure you're the only one on the market.