We'd look at an objective function of LTV to CAC ratio.

We'd ignore everything below a certain absolute MRR.

We'd also ignore anything below a certain MRR growth rate.

The ones we'd typically look at as an investor are: MRR/ARR, Churn, CAC and TLV.

TLV would be total lifetime value which includes the monthly revenue * months given churn.

CAC would be the advertisement cost.

This basically means, how much $ are you spending to make what total $ per customer, and how what is the volume.