I think it's interesting to relate this thread to Fred Wilson's "Why Early Stage Venture Investments Fail":
"Of the 26 companies that I consider realized or effectively realized in my personal track record, 17 of them made complete transformations or partial transformations of their businesses between the time we invested and the time we sold."
With this in mind, I think the most important factor is tractability. Can you build it quickly to test your theory? If your theory is off-base, can you quickly shift? I think Fred is a fairly discerning and successful investor... It's interesting to note that 2/3 of the successful teams that he has invested in have been WRONG about their initial product direction.
"Of the 26 companies that I consider realized or effectively realized in my personal track record, 17 of them made complete transformations or partial transformations of their businesses between the time we invested and the time we sold."
With this in mind, I think the most important factor is tractability. Can you build it quickly to test your theory? If your theory is off-base, can you quickly shift? I think Fred is a fairly discerning and successful investor... It's interesting to note that 2/3 of the successful teams that he has invested in have been WRONG about their initial product direction.