Ok, I will break from the crowd here on the IP issue, while very important. (but can be expensive to get, enforce and follow-up on legally - and also IP is only required for investment by VC only if what you have is truely groundbreaking they are sure it cant be challenged as obvious at the time of filing) - also a VC is more interested in revenue, market size, go-to market and proof points - which means you have to let people use your startups technology.
Not only that, until you see there is value in the technology and a real market/product fit is it sensible spending a lot of money on IP protection? only a question you can answer - but talk with an IP lawyer as they can give yo idea of costs, issues, times, re-submission costs (most IP applications are submitted 2-5 times.)
To get back to your question, there are many places a startup can push an MVP - if a techno;logy startup try producthunt.com you need someone to post for you that is able to do so. Startupli.st/betali.st, earlibird, killer startups and quite a few others few others - google where can I promote my startup for free - there are a few places, but the above should get you a good 100-500 users pretty quick if you have a compelling story and landing page.
If you are afraid of others copying you, don't its down to execution at the end of the day and every team executes differently.
But if still a concern, look for users in your specific market segment and not the technology markets(startup eco-system)