An exercise I learned about from Jeff Weinstein about finding a north star metric goes something like this. Imagine the magical version of a vendor that does what you company does—what do they do? For each one of the things they do, how would they prove it to a customer that doesn’t believe them? Finally, would some of the answers make sense and fit on a billboard?
Now that magical version of a vendor is actually you. What are the gaps between the idealized version of what people want and what you do today? How would you address the gaps and which of them would make what’s on the billboard better? Of course there are the limitations and constraints to work through but this is your north star metric.