Why is CAC at $120?

Pulling back at a $120 CAC was the right call. This tears down what drove it — every paid and funnel metric, in Meta for spend and in both Shopify & GA4 for conversion, each charted against the same dates last year.

CAC = CPM ÷ ( CTR × LP→cart × cart→checkout × checkout→purchase )

Read top-down: CAC rises if reaching people (CPM) costs more, or if any conversion step falls. Spend was cut deliberately, so the "why" lives in these six terms. The reframe vs last year: CPM isn't structurally high — it was actually cheaper than 2025 early in the year, spiked in spring, and has since normalized. The durable gap is conversion: CVR has run below 2025 essentially every week. That, more than media cost, is why CAC sits above last year.

The Benchmark You Actually Want

Conversion rate — this year vs. last

A single March-2026 reference is weak (March wasn't healthy either). Against the full prior-year line, the picture is clear: 2026 CVR sits below 2025 nearly every week of H1 — a persistent ~15–20% gap that no amount of CPM relief fixes.

Weekly conversion rate — 2026 vs 2025 (GA4)

Solid = 2026 · dashed = 2025, same calendar weeks (Jan–Jun). The 5/27-area bump is a promo week both years.

This is the structural driver. Conversion is running ~15–20% under last year across the whole half — so even with CPM back to normal, each click yields fewer customers than it did in 2025, which keeps CAC elevated. The durable lever is the funnel, not the auction.

Your Six Questions

Every metric, answered

Each question maps to one term in the CAC equation, charted with the prior-year line where the data supports it. Paid metrics from Meta; funnel from Shopify (truth) with GA4 cross-check.

So why is CAC at $120? — two layers

Within this year (why CAC rose since spring): the May–June seasonal collision — CPM spiked to ~$48 exactly as every funnel step hit its summer low. That part is seasonal and CPM has already eased back to ~$32.

Versus last year (why CAC is higher than 2025): this is the part the prior-year line exposes — conversion has run ~15–20% below 2025 all half, while CPM was actually comparable-to-cheaper. So the durable reason CAC sits above last year is a conversion gap, not media cost. CTR even improved YoY, so it isn't creative.

→ What a CAO does with this

Stop waiting on CPM — it already normalized. The acute spring spike is over; CPM is back near 2025. Riding it down buys a little, but it won't close the YoY gap.
Treat conversion as the durable lever. Closing the ~15–20% CVR gap to 2025 is worth more to CAC than any media tactic. Start with the two known leaks: the ~Jun 4 checkout-completion dip (below its seasonal floor) and the Listicle's weak session→cart.
Re-scale Meta only once projected CAC clears the profitability line — i.e., after the funnel improvement lands, not on CPM relief alone.
Get the 2025 Shopify funnel-step export so cart→checkout and checkout→complete get true prior-year benchmarks too — the last gap in this teardown.

Sources: CPM/CTR/CPC/Meta-CAC = Meta Ads API (account-level daily→weekly, 2026 & 2025). CVR = GA4 (property 310751693), both years. Funnel steps = Shopify "Conversion rate breakdown" (truth) + GA4 cross-check. Windows: media & CVR = weekly Jan–Jun, 2026 vs 2025; funnel steps = Shopify weekly Apr–Jun 2026 (daily export starts Apr 1); CVR "last week" = daily May 22–Jun 12. GA4 add-to-cart undercounts vs Shopify; GA4 checkout events unreliable since ~May 18 (cart→checkout & checkout→complete are Shopify-only); Shopify funnel-step 2025 benchmark pending a same-period export (checkout→complete uses the 2025 monthly ~46.6%).

Related: D2C Overview · Traffic & Seasonality · YoY Benchmark.