Have you ever played "The Why" game.
Well if you have, you will know what I mean.
If you haven't then lets give it a try.
So, you are going to come to me and say, "I'm starting up a business, because I had this really good idea and I reckon its going to work out just fine". Then you say "What do you think Steve?"
Then I say (you guessed it), "Why?".
So you say, "because I want to get rich". And I say "Why do you think you can get rich? - do you know your market?", to which you reply "sure do matey!". So I say "Why do you know your market?" and you say "well its anyone between the ages of 35 to 100 that wants to purchase a video game". So i say "Why? - how do you know these people will purchase a video game from you?".
Then you say "because everyone loves football games", to which I say "Why - which people buy football video games?". So you say, "85% men and 15% woman". So I say "Why would they buy your football games" and you say, because there is a new feature in our game that isn't in anybody else's game" and I say "Why? - how do you know they want this feature enough to purchase your game?". And so it goes on and on.
The point being that if you truly want to know your market or test your concept you need to play the Why game, at least until you get to a point where you run out of Why's?.
Then if your idea stands up to the Why test!
You might just be on to a winner?