On: No I won't sign your NDA, here's why.

[SkyMarshal]

In a nutshell, the Three T's - technology, traction, and/or team.

You have a new technology that is difficult to implement even with a really good team.

Your product already has strong and growing traction among a market or demographic.

You have a committed team of A+ people already doing customer development, product validation, prototyping, iterating, etc. Not easy.