For Seed-Stage B2B SaaS at $1–3M ARR

B2B SaaS “Blended CAC”
Is a Dangerous Lie.
Here’s What It’s Hiding.

Why B2B SaaS founders with hybrid PLG + sales motions can’t answer basic unit economics questions, and how it’s killing their Series A.

11 min read · February 2026

Maybe you built a product people love. Scaled on product-led growth and the founder’s enterprise relationships. Customer acquisition cost was basically a LinkedIn subscription and sheer force of will.

Then the board starts asking questions. “What’s our CAC by channel?” “What’s the payback period on paid acquisition?” “Can you segment self-serve from enterprise?”

And you can’t answer any of them. Because the trial-to-paid funnel lives in Mixpanel. The enterprise pipeline lives in HubSpot. Ad spend lives on platform dashboards. None of these systems have ever exchanged a single data point.

So what happens? Everything gets blended into one useless CAC number. And everyone prays the board doesn’t ask a follow-up question.

“The board keeps asking for CAC and I keep making up numbers because our self-serve and enterprise deals are all mixed together.” — Sound familiar?

The Pattern

This Isn’t a Spending Problem.
It’s a Visibility Problem.

If you’re spending $5–15K a month on ads across Google, LinkedIn, and Facebook, some of those dollars are producing low-ACV self-serve customers that churn in 3 months. Some are producing $50K ACV enterprise deals that take 9 months to close. They’re all mixed into the same number on the same dashboard.

You can’t fix what you can’t see by segment.

Your systems live in separate universes

Mixpanel tracks product behavior. HubSpot tracks sales pipeline. Ad platforms track clicks. Nobody tracks the full journey from first ad impression to trial activation to enterprise contract signature.

Your “low CAC” from PLG is masking a crisis

Paid ads are bringing in churn-and-burn customers who look great in month 1 but kill your gross retention by month 6. You can’t see it because product usage data isn’t connected to acquisition source.

Enterprise deals are being undercounted by 40%

Marketing can’t track multi-touch attribution across 6-month enterprise sales cycles. So it looks like paid media doesn’t work for enterprise. In reality, you just can’t see the connection.

Your competitor with the worse product but better attribution is raising more money and scaling faster, because they can prove their unit economics and you can’t.

“I feel like I’m flying blind with our ad spend. We’re burning $15K a month and I can’t tell you which campaigns are actually bringing in the enterprise deals.”

The Cost of Waiting

What This Black Box Is Actually Costing You

$54K/yr

Ad spend burned on un-trackable campaigns: 30% of your budget producing outcomes you’ll never be able to measure or replicate

$60K/yr

Founder time spent prepping board metrics that are fundamentally made up. 20 hours a month building spreadsheets you don’t trust

30%

Of your marketing budget wasted chasing signups instead of revenue, because nobody can connect trials to enterprise deals

18+ mo

Effective payback period hidden from view because product usage data isn’t connected to acquisition source

If nothing changes in 6 months

Burn $60–90K in ad spend with no clear ROI. Miss growth targets. Board loses faith and starts talking about “bringing in adult supervision,” code for replacing you as the go-to-market decision maker.

If nothing changes in 12 months

Can’t raise Series A because unit economics are a black box. Competitor with worse product but better attribution outpaces you in revenue. Best engineers leave because growth stalled and equity is underwater.

If nothing changes in 3 years

Company plateaus at $2–3M ARR and gets acqui-hired for pennies. Founder equity is worthless. The product that could have been a category leader dies from lack of distribution.

Picture this: you’re presenting to your board and can’t answer “What’s our true CAC by channel and segment?” The lead investor offers to “help with finance,” which is code for bringing in a replacement CEO.

Why Nothing Has Worked Yet

You’ve Tried. Here’s Why It Failed.

“We hired a performance marketer”

They only knew Facebook Ads. Focused on MQLs and CPL, which are meaningless for a PLG motion where most revenue starts as a free trial, not a form fill. They chased trial signups, which tanked conversion rates by getting the wrong people in the door.

“We used HubSpot’s native attribution”

It can’t track what users do in the product before they convert. Anonymous trial user behavior, product-qualified signals, expansion triggers. HubSpot sees none of it. You’re attributing revenue to the last form fill, not the actual buying journey.

“We hired a growth hacker”

They chased cheap trial signups that looked great in the weekly report but never converted to paid. Worse, it floods the pipeline with bad-fit users that tank activation metrics and bury the product-qualified leads sales should be working.

Every standard solution assumes you have one clean conversion path. But your hybrid PLG + sales-led motion has three: self-serve credit card, sales-assisted, and enterprise. No out-of-the-box tool can handle that without a custom data layer connecting product analytics to your CRM to your ad platforms.

“Every agency wants to run more ads, but nobody can tell me how to connect our product data to our CRM.”

The Fix

Build the Measurement Layer First.
Then Scale the Spend.

The problem isn’t more ad spend. It’s that you have zero visibility into which spend produces which revenue type. Your trial users and enterprise deals CAN be tracked in one system without hiring a $200K analytics engineer.

The belief that “our hybrid model is too complex to track” is wrong. The complexity is exactly why you need a unified tracking layer.

Lux Marketing builds the analytics infrastructure first, then runs the ads. So you can see exactly which marketing dollars produce which revenue type.

Unify the Data

We connect Mixpanel, HubSpot, and your ad platforms into one tracking layer. Every journey from first ad click to trial activation to enterprise contract is visible.

Segment by Revenue Type

We separate self-serve, sales-assisted, and enterprise attribution so you see true CAC, payback period, and LTV by channel and segment, not a useless blended average.

Scale With Board-Ready Data

Walk into board meetings with confidence. Show exactly which campaigns produce enterprise deals vs. self-serve revenue. Scale what works, kill what doesn’t, raise your Series A with clean unit economics.

Why This Works

From Board-Meeting Panic to Board-Meeting Confidence

Before

Blended CAC hiding 30% wasted spend

Can’t tell which campaign sourced a $50K deal

Marketing and sales at war over lead quality

20 hours/month prepping made-up board metrics

Competitor with worse product raising more money

After

True CAC by channel and revenue segment

Every enterprise deal traced to first touchpoint

Marketing and sales aligned on shared data

Board-ready dashboards that update themselves

Raising Series A with clean, provable unit economics

“I just spent 20 hours prepping for the board meeting and still couldn’t answer basic questions about our unit economics.” — That was the last board meeting without real data.

Is This You?

This Is Built for a Very Specific Company

✓ B2B SaaS with hybrid PLG + sales-led motion, $1–3M ARR
✓ Post-seed ($1–2M raised), planning Series A in 12–18 months
✓ Spending $5–15K/month on ads but can’t segment CAC by revenue type
✓ Mixpanel, HubSpot, and ad platforms exist as data silos with no shared layer
✓ First marketing hire can run campaigns but can’t build data infrastructure
✓ Ready to invest 90 days in building the measurement layer before scaling spend

Ready to see what your blended CAC is hiding?

Get Your Free Analytics Audit

15-minute audit. No commitment. We’ll show you exactly where your attribution is broken.

One More Thing

The Clock Your Board Set Is Real

If you have 18 months of runway and the board expects $5M ARR, every month without a measurement layer is a month of data you’ll never get back.

Marketing hires in this position often cycle through the same loop: launch campaigns, see ambiguous results, get questioned, turn off the ads, repeat with zero learning. Sales says marketing leads are “low quality.” Marketing says sales isn’t following up. Neither side can prove anything because neither has the data.

If you understand cohort analysis and retention curves, you’re rigorous about data everywhere in the business except the biggest budget line item. That’s not a spending problem. That’s an infrastructure problem.

And it’s the one thing standing between you and a Series A term sheet.

Stop Making Up CAC Numbers
for Your Board.

Get a free analytics audit showing exactly where your attribution is broken and how to connect your product data, CRM, and ad platforms, in 90 days, not 12 months.