The Hidden Metric Killing Your CPAs

Last week, I had three discovery calls that all circled back to the same fundamental issue: brands scaling spend but watching their CPAs climb without understanding why.

One apparel brand was doing everything right on paper. Their CPCs were stable at $2, CPMs holding at $25, CTR actually trending up. But their CPAs? Shot up 30% heading into last Q4.

The real issue is a metric most brands aren’t even tracking…

Cost Per Thousand Accounts Reached (CPMA) is different from CPM. CPM measures impressions. CPMA accounts for frequency: it tells you how expensive it actually is to reach net new people.

When I pulled the data for this brand:

• They averaged $170 CPMA all year

• Then suddenly: $270, $240, $300

• CPAs climbed 30-50% in lockstep

The ad platform wasn't getting more expensive. They were just hitting the same people over and over. When we broke down spend by audience:

• Existing customers: CPMA jumped from $1,500 to $3,000

• Engaged audiences: Held steady around $350

• Prospecting: Barely moved

The platform was concentrating spend on existing customers automatically.
Why?

When we audited their exclusions:

1. Their "all-time customers" list hadn't been updated since January. Anyone who purchased after that? Still in prospecting.

2. Their "engaged audience" was missing critical segments: website visitors, video viewers, add-to-carts.

Meta's algorithm is smart. When you tell it someone's a prospect who's actually already bought from you twice, it's going to target them because they convert. But you're paying prospecting prices for remarketing.

This is why Klaviyo integration matters. It's the only CRM that dynamically syncs all-time purchasers. Someone buys tomorrow at 3pm? They're excluded from prospecting by 3:15pm.

Another brand on the call: "Can we just run DPAs? They've crushed it for us for years."

I get it. Product catalog ads are easy. They work. But here's what I told them after sitting with a client at Meta HQ:

DPAs aren't prospecting.

When you break down DPA performance by audience type, it's almost exclusively middle and bottom of funnel.
Your existing customers. Your engaged audiences.
The algorithm defaults to the path of least resistance.

This is fine if you know it. But if you think you're prospecting when you're really just remarketing at scale, your CPMA will skyrocket and you won't understand why.

Solution? Use catalog customizers like Marpipe or Socioh to create DPA variants with different creative treatments. Split screens, themed backgrounds, seasonal overlays. Scale horizontally, not just with budget.

Third call this week: CPG brand running 4:1 ROAS at $300/day. "Why aren't we spending more?"

Valid question. But here's what I asked back:

• What's your welcome series look like?

• How many emails are you sending per month?

• Do you have abandoned cart flows with product education?

• Are you segmenting by intent? (Weight loss vs. protein vs. general lifestyle)

They were sending 1 email per month.

Our clients send 10-15 unique campaigns monthly. Not because we're email-obsessed, but because it's math.

If 99% of people don't buy on their first visit, you need a system to capture that intent and nurture it.

Before you dump $1K/day into Meta, build:

1. A robust welcome series (5-7 emails over 10 days)

2. Abandoned cart recovery with education, not just discounts

3. Intent-based segmentation so your messaging matches why they came to you

This is the difference between burning cash and building a business.

If your CPAs are climbing but your CPCs and CPMs look fine:

1. Check your CPMA by audience segment

2. Audit your audience exclusions (especially your all-time customers list)

3. Look at your DPA performance by audience type, not blended

If you're scaling spend without infrastructure:

1. Pause. Build flows first.

2. Segment by intent

3. Then scale

These aren't advanced tactics. They're fundamentals that get overlooked when everyone's focused on creative and audience testing.

Quick snapshot from this week across our portfolio: costs declined across the board, CVR improved, while CTR softened slightly. Efficiency continues to trend in the right direction.

P.S. If you want to see how we diagnose these issues in real accounts, reply to this email. Happy to walk you through a free audit.

That's it for this week. Hope it helps.

- Uri & The Growth Collective Team