What’s the best way to think about profitability?

Fred Wilson (Co-Founder and Partner at Union Square Ventures)
Measuring Price Elasticity And More – AVC

Price > CAC + COGS … That means the price you charge must be greater than the cost you must pay to acquire a customer plus the cost you must pay to make or deliver the service. If your product or service is sold on a subscription basis, then you must also know the amount and timing of churn to expect and the lifetime value of a customer (LTV). In a subscription offering, the above formula becomes LTV > CAC + COGS