Customer Acquisition Cost (CAC)

Customer acquisition cost is everything you spend on sales and marketing to win a customer, divided by the number of customers won in a period. It is the metric executives use to judge whether a growth channel is worth funding.

Frame SEO’s value in CAC terms, because that is the language leadership funds. Organic search has high upfront investment but near-zero marginal cost per additional customer, so as organic compounds, your blended CAC falls — the opposite of paid, where CAC is roughly fixed per click. Track blended CAC and payback period over time, and attribute organic’s contribution honestly so the channel gets the credit it earns.

CAC, alongside its ratio to lifetime value and its payback period, is how SEO wins and keeps executive buy-in. An organic channel that lowers blended CAC quarter over quarter is a compounding asset, not a line-item cost — and that framing, not rankings or traffic, is what protects your budget in a downturn. Senior practitioners connect SEO directly to CAC and payback in board-level reporting, turning a "marketing expense" into a durable financial advantage.