I have my own belief about the idea, actually I have a vision on how it's going to be, the goal that I am seeing, I am passionate about it too. I can talk fore

I have my own belief about the idea, actually I have a vision on how it's going to be, the goal that I am seeing, I am passionate about it too. I can talk forever about it, and how I envision it. However the doubts I am having is whether people see it as well, whether people will buy my idea when I shop around. My background is in Product Management. I am good at defining product, building products, and then marketing ideas. I do however have a engineering background, MSc in EE. My idea though is about internet, social networking. I have doubts that when I first open my mouth and talk about social networking, people will just said, forget it, Facebook rules, without even listening to what I have to say. When your buyers already have a stereotype on that, it makes it very hard to pitch and now it creates doubts in me...