Great ideas don’t build companies; great unit economics do. The heartbeat of any subscription business is the relationship between what a customer is worth (LTV) and what it costs to find them (CAC).

To survive, your Lifetime Value must significantly outweigh your Acquisition Cost. The fundamental formula for LTV (assuming infinite horizon) is:
$$LTV = \frac{ARPU}{Churn}$$
Where $ARPU$ is Average Revenue Per User and $Churn$ is the % of customers leaving per month. The industry standard is that