1/ One of the leading indicators of product-market fit in SaaS is when your first couple of SDRs are getting uber productive super fast. 2/ Keep a close eye on: (1) Conversion rate from cold calls/emails to demos (2) # of demos each SDR can set up every week consistently.
3/ Of course, there are other metrics that matter: ARR growth rate, user engagement (v. important!), rep productivity etc.
4/ But the earliest indications of whether the product value prop is resonating with buyers can come from the SDR productivity metrics.
5/ What other qualitative/quantitative factors can be early indicators of product-market fit in SaaS?