The CFO Meeting: Auditing a Paid Social Channel's Real Unit Economics

Marketing Academy · Field Work●Marketing Fundamentals

All projects·From: Marketing Math: CAC, LTV, ROAS, Payback

CoreAudit· 35 minutes

Freshworks

Objective: Given a real 9-day campaign export and a set of finance inputs, calculate fully loaded CAC, LTV, ROAS, and payback period for one acquisition channel, then decide whether it deserves more budget, less, or a hold, exactly the way a CFO would read the same numbers.

You're the growth marketer at Freshworks (styled after its real freemium-to-paid SMB SaaS motion) preparing the unit-economics slide for a budget review. Marketing wants to double the "Social - Prospecting Lookalike" ad group's budget next quarter. Finance wants proof it's not just buying vanity signups.

Four numbers, one campaign export, one finance handoff. Walk CAC, LTV, ROAS, and payback in order, exactly like the lesson's own workflow, then write the one sentence that either gets the budget increase approved or kills it.

Before you start

What you'll need

Free path (everything below is enough to finish)

Google Sheets

FreeWhere you filter the CSV export and run the four formulas

Not in the tools directory, genuinely free, opens the CSV and every formula in this project directly.

Google Analytics 4(optional)

FreeWhere you'd confirm trial-to-paid and revenue figures in a real account

Free tier is enough to cross-check the CRM/revenue numbers used in this audit against real event data.

Paid upgrades (optional, faster/deeper)

The free path (a spreadsheet and the CSV export) completes this project in full. Triple Whale or a similar attribution tool is only worth it once this becomes a recurring weekly task.

Triple Whale(optional)

PaidAutomates this exact CAC/LTV/ROAS rollup across channels on an ongoing basis

Useful once you're running this audit every week across five channels instead of once by hand, never required to complete this project.

Download project dataset

The process

4 steps

Step 01 of 04

1. CAC, Customer Acquisition Cost

CAC = Total Sales and Marketing Spend / New Customers Acquired. "Total spend" means everything, ad spend alone ("paid CAC") gives you a flattering number finance will not trust.

What did it actually cost, fully loaded, to win each of the 9 customers this ad group produced?

Google Sheets— public/project-data/ad-account-export.csv, filter ad_group = "Social - Prospecting Lookalike", 2026-06-01 through 2026-06-09

Procedure

Filter the export to the "Social - Prospecting Lookalike" ad group and sum the cost column for 2026-06-01 through 2026-06-09.
Cross-check against the CRM: of the resulting trial signups, note how many converted to a paid plan within 30 days.
Add finance's allocated share of the growth marketer's salary and the ad-creative tool retainer for this channel, ask finance for the number, don't estimate it.
Divide fully loaded spend by paid customers, not trial signups, that's the CAC number finance will actually accept.

Sample output

Social - Prospecting Lookalike · 2026-06-01 to 2026-06-09 (9 days)

  Ad spend (from export)        $258.07
  Trial signups                     72
  Trial-to-paid (CRM, 30-day)        9
  + Allocated salary/tools      $416.93
  = Fully loaded spend          $675.00

  Paid CAC (ad spend only)   $258.07 / 9 = $28.67
  Fully loaded CAC           $675.00 / 9 = $75.00

Healthy

Fully loaded CAC sits comfortably under the $205 SaaS industry average CAC benchmark the lesson cites.

Unhealthy

Fully loaded CAC runs 2-3x the paid-only number and keeps climbing quarter over quarter with no change in trial-to-paid rate.

What this means

$75 fully loaded is well under the $205 SaaS benchmark, on cost alone this channel already looks efficient. But CAC in isolation never tells you whether to spend more, only LTV and payback do.

So what do I do about it?

Symptom	Action	Effort
the deck reports paid CAC ($28.67) instead of fully loaded CAC ($75.00)	restate the slide with fully loaded CAC before finance catches the gap themselves	5 min
trial-to-paid rate (9 of 72, 12.5%) isn't broken out anywhere	add it as its own line, it's the number that will get questioned first	5 min

YouYou can do this yourself, no engineering access required.

Step 02 of 04

2. LTV, Lifetime Value (also called CLV or Customer Lifetime Value)

LTV = (Monthly Revenue per Customer x Gross Margin %) / Monthly Churn Rate for subscription businesses. Gross profit, never top-line revenue, or the ratio evaporates the moment finance checks it.

What is each of those 9 paying customers actually worth, in gross profit, over their full relationship with the company?

Google Sheets— Finance's SaaS metrics sheet: average monthly revenue per customer, gross margin, and monthly churn for this plan tier

Procedure

Pull average monthly revenue per customer for the SMB plan tier this ad group sells into: $49/month.
Pull gross margin from finance for this plan tier: 78% after hosting and support costs.
Pull monthly churn rate for this cohort's plan tier: 3%.
Apply the formula: (Monthly Revenue x Gross Margin) / Monthly Churn Rate.

Sample output

SMB plan tier inputs (from finance)

  Avg monthly revenue/customer   $49.00
  Gross margin                      78%
  Monthly churn rate                 3%

  Monthly gross profit/customer  $49.00 x 0.78 = $38.22
  LTV                            $38.22 / 0.03 = $1,274.00

Healthy

LTV:CAC ratio (next step) clears 3:1, and the margin figure used is gross profit, not revenue.

Unhealthy

Someone plugs $49 revenue directly into the ratio instead of $38.22 gross profit, an inflated ratio that isn't real.

What this means

$1,274 LTV against a $75 CAC is a 17:1 ratio, more than five times the 3:1 healthy benchmark. This isn't just healthy, it's a signal the channel is being under-funded relative to what each customer is worth.

So what do I do about it?

Symptom	Action	Effort
LTV:CAC is above 5:1	this is the lesson's own "under-investing in growth" branch, bring a specific budget-increase number to the CFO meeting, not just a status update	30 min

YouYou can do this yourself, no engineering access required.

Step 03 of 04

3. ROAS, Return on Ad Spend

ROAS = Revenue Generated by Ads / Ad Spend. It's the speedometer, a fast read on efficiency, not the destination, it ignores everything that happens after the first purchase.

Read on its own, does this channel's ROAS look like it deserves a bigger budget?

Google Ads— First-month revenue from the 9 paying customers against the $258.07 ad spend that produced them

Procedure

Multiply paying customers by first-month revenue: 9 x $49.
Divide by ad spend for the same window: $258.07.
Compare against the 2.04 median e-commerce ROAS and 4:1 typical e-commerce target the lesson cites, then note this is a SaaS motion, not e-commerce, so the target itself needs adjusting, not just the number.

Sample output

First-month revenue (9 customers x $49)   $441.00
  Ad spend (9-day window)                  $258.07
  ROAS                                       1.71x

Healthy

For a SaaS motion with a 3%-a-month churn tail, a ROAS just above 1x in the first 30 days is expected, most of the return arrives in months 2 through 24, not month 1.

Unhealthy

A ROAS below 1x on a channel with no long-tail retention story (a one-time-purchase product, for instance) and no plan to improve it.

What this means

1.71x looks unimpressive next to the 4:1 e-commerce benchmark, but that benchmark is for a different business model. Read alone, ROAS would talk you out of a channel the LTV:CAC number just told you to fund more.

So what do I do about it?

Symptom	Action	Effort
someone on the team wants to pause the channel because "1.71x isn't a good ROAS"	walk them through LTV:CAC in the same conversation, ROAS answers "did this week work," not "should we keep doing this"	5 min

YouYou can do this yourself, no engineering access required.

Step 04 of 04

4. Payback Period

Payback Period (months) = CAC / Monthly Gross Profit per Customer, how many months of margin it takes to cover what you spent acquiring the customer.

How many months of margin does it take before this channel's customers stop being cash-negative?

Google Sheets— The CAC ($75.00) and monthly gross profit per customer ($38.22) already calculated above

Procedure

Divide fully loaded CAC by monthly gross profit per customer.
Compare against the under-12-month ideal and the ~20-month 2025 SaaS median the lesson cites.
Write the one-sentence recommendation for the CFO slide.

Sample output

Payback = $75.00 / $38.22 = 1.96 months

Healthy

Under 12 months is the ideal the lesson cites; under 18 months with a 3:1+ LTV:CAC is the floor for "safe to scale."

Unhealthy

Payback exceeds 18 months while LTV:CAC sits below 3:1, a unit economics problem, not a marketing problem.

What this means

Under 2 months against a ~20-month 2025 SaaS-wide median isn't just healthy, it's the third piece of evidence, after CAC and LTV:CAC, all pointing the same direction: this channel can absorb a lot more budget before it stops being efficient.

So what do I do about it?

Symptom	Action	Effort
the budget review keeps stalling on "is this channel working"	bring all three numbers together, CAC $75, LTV:CAC 17:1, payback under 2 months, as one slide, not three separate updates	30 min

YouYou can do this yourself, no engineering access required.

Final deliverable

A one-slide unit-economics summary: CAC (paid + fully loaded), LTV, LTV:CAC ratio, ROAS, and payback period, plus a two-sentence budget recommendation.

See a reference example

Sample output

Fully loaded CAC: $75.00 (vs. $205 SaaS benchmark). LTV: $1,274 (78% margin, 3% monthly churn). LTV:CAC: 17:1, more than 5x the 3:1 healthy floor. ROAS: 1.71x in month one, unremarkable read alone, expected for a subscription motion. Payback: 1.96 months, a tenth of the ~20-month 2025 SaaS median. Recommendation: this channel is under-funded relative to what it returns; a company at Klaviyo's scale would treat a 17:1 ratio this consistent as a green light to double the budget, not a number to double-check for the third time.

Success criteria

You're done when you can:

Uses fully loaded CAC ($75), not paid-only CAC ($28.67), in the final recommendation
Calculates LTV from gross profit ($38.22), not raw revenue ($49)
Correctly reads ROAS (1.71x) as inconclusive on its own, not as a reason to cut the channel
Final recommendation is "increase budget" with a specific number tied to the LTV:CAC ratio, not a vague "this looks fine"