What costs should be included in CAC?

Fully loaded sales and marketing: salaries, commission, benefits, tooling, agencies and programme spend. Excluding salaries — common, because it flatters the number — makes it a media-efficiency measure rather than an acquisition cost.

Should customer success be included in CAC?

Only the portion working on new-customer onboarding, and only if you can separate it. If success is primarily retention and expansion, it belongs in cost of retention. State which you chose, because it moves the number materially.

How do you handle the lag between spend and closed deals?

Offset the spend period by your median sales cycle. Dividing this quarter's spend by this quarter's wins attributes cost to deals it did not create, and the error grows with cycle length.

Is a lower CAC always better?

No. CAC falls when you stop investing in growth and when you pursue only easy segments. It is only interpretable next to the value of what was acquired and the volume acquired.

Customer Acquisition Cost (CAC)

The fully loaded cost of acquiring one new customer: sales and marketing spend for a period divided by new customers acquired from it.

The calculation

Total sales and marketing cost for a period, divided by the number of new customers acquired in that period. Simple arithmetic over four decisions that are rarely made explicitly, which is why the figure is so often incomparable between two companies — or between two quarters at the same company.

The four decisions

What changes the number

Decision	Common practice	Consequence
Salaries in or out	Often excluded	Excluding them can halve the figure
Period alignment	Same-period spend and wins	Misattributes cost when cycles are long
New vs expansion	Expansion deals counted as new	Understates true acquisition cost
Blended vs by-channel	Single blended figure	Conceals that one channel is subsidising another

Source: Distinctions stated here

Fully loaded

Salaries, commission, benefits, tooling, agency fees and programme spend for everyone whose work is acquiring customers. The word exists because the partial version — media spend only — is a different and much smaller number that is frequently reported under the same name.

Computing it defensibly

Agree the cost base and write it down: which teams, which line items, which tools. This is the step that makes the figure comparable over time.
Offset the spend window by your median sales cycle, so cost is matched to the deals it plausibly produced.
Count new logos only. Expansion has its own, much lower, cost of sale and mixing them makes both meaningless.
Compute it by channel and by segment as well as blended. The blended figure hides the case where one efficient channel funds several that do not work.
Report it beside payback period. Cost alone says nothing about whether the acquisition was worth making.

Where it misleads

Falling CAC is ambiguous — it happens when acquisition gets more efficient, and equally when you stop spending or start declining hard deals.
Brand and content spend produces customers over years; charging it to one quarter's cohort overstates that quarter's cost and understates later ones.
In product-led motions much acquisition cost is engineering, which sits outside sales and marketing and never enters the figure.
A blended figure across very different segments describes no actual customer.

RELATED TERMS

LTV:CAC Ratio

Lifetime value divided by acquisition cost. Whether a customer returns more than they cost to win.

CAC Payback Period

How long it takes for a customer's gross profit to repay the cost of acquiring them. The bridge between sales efficiency and cash flow.

Cost Per Lead (CPL)

Marketing spend divided by leads generated. The most immediately available demand-gen metric and the easiest to misread.

Magic Number

A sales efficiency measure comparing new recurring revenue produced to the sales and marketing spend that produced it.

COMMON QUESTIONS

What costs should be included in CAC?: Fully loaded sales and marketing: salaries, commission, benefits, tooling, agencies and programme spend. Excluding salaries — common, because it flatters the number — makes it a media-efficiency measure rather than an acquisition cost.
Should customer success be included in CAC?: Only the portion working on new-customer onboarding, and only if you can separate it. If success is primarily retention and expansion, it belongs in cost of retention. State which you chose, because it moves the number materially.
How do you handle the lag between spend and closed deals?: Offset the spend period by your median sales cycle. Dividing this quarter's spend by this quarter's wins attributes cost to deals it did not create, and the error grows with cycle length.
Is a lower CAC always better?: No. CAC falls when you stop investing in growth and when you pursue only easy segments. It is only interpretable next to the value of what was acquired and the volume acquired.