Marketing, sales people, and such are all great but if you don't have product-market fit yet, you're beating up a dead horse here by focusing on growth. One of the first things I do when starting a new SaaS is setting up an event tracker (think mixpanel). At this stage, you barely have any users so no need for fancy analytics stuff. I just stare at the event log until I figure stuff out. Why are they not clicking on that button? Why are they skipping this card? Lots and lots of problems can be discovered and tracked by this way.
After all this, if I have a weekly user retention hovering around 30%, I can't be more happy. Then it's time to grow.