Probabilistic, Anonymous, Modeled… What You Need Is Deterministic Data

Hi there,

I've had some version of the same conversation with a few different brands this month, and it finally clicked into one idea for me: almost every "offline data" problem I run into right now traces back to the same root cause. The data was never deterministic to begin with.

Deterministic data means a real customer, tied to a real purchase, verified. Not modeled. Not rented. Actually yours.

That gap shows up in two different corners of a marketing stack, but is ultimately leading to the same problem: you aren't using real, owned first-party data when you're making decisions.

Your probabilistic tools are only as good as what you feed them

MMM, MTA, attribution or other measurement tools, and every ad platform's optimization engine, Meta's Andromeda, Google's Performance Max, TikTok's models, are probabilistic by design. They estimate what happened based on modeled data because retail and marketplace data is invisible. These tools aren't doing anything wrong…

But an estimate is only as good as its inputs. Feed these systems nothing but your DTC pixel, and they're modeling off a fraction of your actual business while treating that fraction as the whole picture. The algorithm doesn't know it's missing 80% of your purchases. It just quietly optimizes toward whatever sliver of signal you gave it, and gets worse at finding your real customer over time without ever telling you that's what's happening.

Feed the same system one verified, deterministic purchase event instead of an inferred one, and the guess gets dramatically less wrong. That's not abstract: 44% of CPG marketers already say they question whether their own incrementality numbers are reliable [1]. That's most of the industry admitting their models are guessing, and increasingly aware of it.

Deterministic data doesn't replace MMM or attribution. It's the fuel that makes them worth trusting.

Anonymous data was never deterministic either

Here's the second version of this problem, and it's the one brands notice less, because it feels like it's already solved.

One of my team members told me he uses Walmart+, and still gets "manufacturer $2 off" coupons at checkout for detergent he was buying anyway. That's not incremental. That's the system working exactly as designed, for someone else's benefit.

A lot of "we already have offline data" answers I hear are really "we work with a cashback or receipt-scanning partner," like Fetch or Ibotta. And while that data can be accurate, the platforms are completely anonymizing your customer data.

These tools have trained brands to think "offline purchase data" can only mean anonymized, panel-style signal data: directional, aggregate, someone else's audience. But that isn't the case. Deterministic, brand-owned purchase data (tied to your actual customer, feeding your own CAPI and CRM) is a categorically different asset, not a nicer version of the same one.

Your customer. Your signal. Your CAPI. The relationship lives with you, not inside somebody else's walled garden.

Same root cause, two symptoms

Probabilistic tools guess because nobody gave them real data inputs. Panels feel like an answer, but they were never your relationship to begin with. Different failure modes, same fix.

Deterministic, first-party data is the one input that solves both at once. It's the real signal your models are missing, and it's the audience nobody else gets to hold onto instead of you.

Feed that same signal back into your stack, and everything downstream gets sharper: measurement stops guessing, retention finally has a real list to work with, and every ad platform starts optimizing toward an actual customer instead of a modeled one.

Talk soon,

Kait

A few extras:

Some of my favorite brands are hiring…

1. QVC - Sr. Manager Retention Marketing
2. Little Spoon - Sr. Lifecycle Marketing Manager, Retention

Sources:

[1] eMarketer: "MMM, incrementality, and other measurement trends that will define 2026"