Part 1 — Payback economics set every target
Compute honest CAC payback, place yourself against current benchmarks, and derive the CAC target every campaign inherits.
SaaS paid acquisition has exactly one governing metric: CAC payback — months until a new customer’s gross margin repays what you spent to acquire them. It prices growth in cash, which is the currency you can actually run out of. LTV:CAC is the sanity check; payback is the steering wheel. Every target in this course derives from it.
Compute it honestly or not at all
Fully loaded sales and marketing cost (salaries, tools, agency fees, creative — not just ad spend) divided by new customers, then recovered at monthly revenue times gross margin. The revenue-unadjusted version flatters by 20-40%. Run your own numbers through the CAC payback calculator, then place yourself against the current benchmark bands — the 2026 medians sit around 15-16 months for B2B SaaS, detailed by segment in SaaS marketing metrics that matter.
From payback ceiling to channel CAC target
- Set the payback ceiling your cash position tolerates (bootstrapped: often under 12 months; funded: 18+ may be acceptable).
- Invert it: ceiling months × monthly margin per customer = allowable fully-loaded CAC.
- Deduct the non-media costs per acquisition (sales time, tools share) to get the allowable MEDIA cost per customer.
- Divide through your funnel: allowable media CAC × close rate × qualification rate = the cost per lead or trial your campaigns must hit. That number — not a benchmark, not last quarter’s average — is every campaign’s inherited target.
Do the four-step derivation before touching a campaign. When a channel misses the derived target, the answer is visible in the chain: either the channel is too expensive, the funnel leaks, or the ceiling was fantasy. Without the chain, every miss becomes an argument.
One structural warning: SaaS conversion events are cheap to fake and expensive to trust. A $40 trial signup that never activates is not acquisition, it is spend with better manners. Part 3 deals with choosing the conversion event; part 5 deals with feeding real pipeline outcomes back to the platforms. Both assume the economics you just computed.