- Your co-founder is blinded by the idea, just like you
- Your parents probably do not really understand the concept but love everything you do
- The speech coach really understands articulation, stance, and story flow, but will not spot that huge gaping hole in the business model
- The friend of a friend of a friend who is an angel investor will suggest that you should make a comparison to that company featured in TechCrunch 2 months ago
- The friend of a friend who owes a favor and is a VC does not really have time to go into the idea and will suggest to beef up the competitive analysis a bit, unfortunately he does not invest in businesses that are this early, come back in 6 months...
- The casual friend who wants to be friendly but does not know you very well, does not have the courage to say what she really thinks
- The management consultant sees problems everywhere and will suggest more analysis and risk mitigation
Still, each of the above has valuable input, just put it in context.