Contribution Margin

revenue less variable costs - can be expressed as a $/period or as a % of revenue

• note that CAC is a variable cost
• hopefully enough to more-than-cover your fixed costs, leaving you some profit

the throughput in Throughput Accounting - see Logical Thinking Process

https://corporatefinanceinstitute.com/resources/accounting/contribution-margin-overview

https://www.investopedia.com/terms/c/contributionmargin.asp