Focus on retention. My app[1] is sticky in that once you're set up it's a bit of hassle to leave and even then you'd only likely do it at one point during the year. This makes long-term retention fairly easy and worth some up front time investment in accommodating specific requests.
As an example, one new customer wanted a general "notes" page for each employee. Not hard to build, other customers might find it useful and they now have c. 250 employees on their account. Moving them to a different service is not simple.
Interestingly, my longest-serving customer is also one of my first. They've been with me nearly six years. My LTV averages around £550 because of that stickiness.