Cost of Customer Acquisition vs. Monetization metrics

This is an interesting article for start-ups about balancing the costs of new customer acquisitions and the resultant monetization (lifetime value) of new customers. There is a very understandable infographic that purports to show how marketing efforts drive acquisition costs. The author includes two example spreadsheet calculators that show how you might measure acquisition costs. In particular, the authors argue that inbound marketing lowers the acquision costs, while outbound marketing raises those costs.