How to Measure Product Market Fit for Your Startup

Steve Blank is author of Forceps the Epiphany. He says that one-size-fits-all approaches are like, just use retention or just use certain metrics. Do not work for all startups,. You have to really think about what it is that your startup needs. What does it mean for someone to use your product in the way that you intend them to use it? And how would that actually show up in these sorts of retention metrics?