The last time I talked with 5 potential customers they all agreed that my idea would really fit their needs but they can't see how this ever would work. Explain

The last time I talked with 5 potential customers they all agreed that my idea would really fit their needs but they can't see how this ever would work. Explaining to them couldn't change their mind.. I like your approach, but sometimes a little demo is necessary. edit: I'm dissapointed this isn't about entity framework ;)