Customer Acquisition Cost (CAC)

What Customer Acquisition Cost Measures

Receipts. CAC is the all-in cost — sales salaries, ad spend, BDR commissions, demo gifts, RevOps tooling, the slice of the marketing team's salary that touches new-logo work — divided by the number of new customers the business closed in that period. A SaaS company that spent $2M on sales and marketing in Q1 and closed 100 new logos has a CAC of $20,000. That number sets the floor for unit economics: if a customer's lifetime value doesn't exceed CAC by a meaningful multiple, the business is renting growth from its bank account.

How CAC Is Calculated

The formula is mechanically simple and operationally contested.

CAC = (Sales spend + Marketing spend) / New customers acquired

The fight is over what counts as "sales and marketing spend." The defensible version — the one investors price on — includes:

Companies that exclude commissions or tooling produce a flattering CAC and an angry Series B board meeting six months later.

A Worked CAC Example

A mid-market SaaS company spends $4.2M in H1 across sales and marketing. They close 140 new customers. CAC = $30,000. Their average ACV is $42,000. That's a 1.4x first-year ratio — survivable but not great. Strong B2B SaaS benchmarks sit around 3-5x LTV-to-CAC, or one-year payback when blended with NRR.

Segment the same company by motion and the picture changes. Inbound CAC is $11,000 (60 customers). Outbound CAC is $52,000 (80 customers). The blended number lied. Outbound is the part that's actually breaking, and the next budget conversation should be about whether outbound is profitable at the current ACV — not whether marketing is delivering.

When Sales Orgs Use CAC

CFOs and VPs of Finance use CAC to model burn and runway. Boards use it to decide whether to greenlight another sales hire or pull funding back. RevOps teams break CAC down by channel, segment, and ICP fit to figure out where to push. CROs care about CAC payback period — months until a customer's gross margin covers their acquisition cost. Recruiters quietly check CAC trends before joining a sales org, because a company with $90K CAC on a $40K ACV is one round of layoffs away from a hiring freeze.

Individual reps rarely see CAC, and that's fine. It's a system metric, not a coaching metric.

Common CAC Gaming Patterns

CAC is gamed three ways. First, by exclusion: companies leave commissions, contractors, or "growth" headcount out of the numerator and report a number that bears no relationship to GAAP financials. Second, by lag: counting new customers from a quarter while only counting marketing spend from the prior quarter — same denominator, smaller numerator, prettier ratio. Third, by mixing organic and paid: a brand-led inbound win gets credited against last quarter's paid spend, making paid acquisition look efficient when it isn't.

The honest version costs more to produce and answers a different question. Not "how good is our marketing," but "what does growth actually cost us." That's the only CAC that survives a due-diligence call.