Ran across these great blog posts (The Illusion of Product/Market Fit for SaaS Companies, The SaaS Adventure) by Brad Feld & Neeraj Agrawal respectively. Product/Market Fit is now, appropriately, a central concept in startups. But when do you have it?

1. If you think you have it, odds are darn good you don’t. Is your data really robust enough for you to know you have it?
2. If you do have it, odds are good you don’t have it good enough to scale!
3. If you do have it, and you are actually ready to scale… be ready for the world to change and for you to lose Product/Market fit… at scale!

Not trying to be a downer, but getting these questions wrong can kill your company. Luckily, those two posts have some great rules-of-thumb for keeping you honest and on track.