Has anyone asked the Winklevoss twins what they think of "no-one will steal your idea, tell everyone!"
I know "no-one will steal your idea" is the accepted wisdom but I don't buy it.
I think "no-one will steal your idea" because in the vast majority of cases, your idea is crap.
If your idea is absolutely compelling then people with the resources and motivation will steal it. Why wouldn't they? If you told me an idea that was a huge opportunity, and if you were not a friend whom I had loyalty to, then I would build your idea for myself. I have the time and the ability to, so why wouldn't I?
I think build your software to the point that it implements the vision you have in mind then release it. That's my idea of MVP - minimum valuable product.