# GreenLeaf UK — Media team analysis

**Reviewed editorial draft; human release pending.** Fictional UK paid-click cohorts; Week 1 =
September 1–7, Week 2 = September 8–14, 2026. Seven-day observation windows, September 22 snapshot.

## What happened

| All supplied paid cohorts | Week 1 | Week 2 |
|---|---:|---:|
| Spend, USD | $5,462 | $5,512 |
| Quiz starts | 15,040 | 15,120 |
| Quiz completions | 6,770 | 5,460 |
| Attributed first-purchase customers | 467 | 357 |
| Attributed first-purchase revenue | $37,360 | $28,560 |
| Media CPA | $11.70 | $15.44 |
| Attributed first-order ROAS | 6.84 | 5.18 |

Media CPA includes media cost only; do not compare it directly with the course’s $312 full-CAC
guardrail. ROAS is attributed first-order revenue divided by media spend, not profit or causal lift.

| Channel | W1 spend | W2 spend | W1 customers | W2 customers | W1 revenue | W2 revenue |
|---|---:|---:|---:|---:|---:|---:|
| Google Search | $1,736 | $1,744 | 154 | 105 | $12,320 | $8,400 |
| LinkedIn | $2,296 | $2,304 | 154 | 119 | $12,320 | $9,520 |
| Reddit paid | $1,430 | $1,464 | 159 | 133 | $12,720 | $10,640 |

No approved monthly media budget is supplied, so budget pacing cannot be assessed.

## Why the mobile comparison needs a mix check

Mobile completion: **3,780/8,400 = 45% → 2,352/8,400 = 28%**. The change is **−17 percentage
points**, approximately **−37.8% relative**. Desktop is **2,990/6,640 = 45.03% → 3,108/6,720 = 46.25%**.

Mobile skeptical starts fall from **4,200 to 2,100**; exploring starts rise from **4,200 to 6,300**.
Their shares change from **50%/50% to 25%/75%**. These are constructed buckets, not validated
customer preferences or randomized treatments.

Each of the **12** channel × audience × creative mobile strata has **700** Week 1 starts. Use
weight **700/8,400 = 1/12** and multiply by that stratum’s Week 2 completion rate. Sum the weighted
rates: **35.33%**, retaining full precision before display. See the metric pack for every cell.

In this Week 1-weighted decomposition, the within-group component is **−9.67 points** and the
composition component is **−7.33 points**. The allocation depends on the chosen baseline/order;
neither number is a causal effect. All 12 strata decline, but the CSV cannot explain why.

## What happens next

- **Media lead:** verify event definitions and source/cohort tagging; retain the same maturity rule.
- **Product owner + media lead:** request release/version assignment and reproduce the mobile flow.
  Compare versions where assignment can be reconstructed. Missing logs limit what can be concluded.
- **Measurement reviewer:** check the calculations, context and decision before stakeholder release.
  Do not infer a product cause, recommend a precise budget move, or treat a recovery to target as a
  valid test design on its own.

The reported mobile presentation revision and support concern prioritize these checks. They do not
prove a defect, prevalence or incremental loss. No external action or delivery occurred.

Source: [dictionary](dictionary.md), [checked metric pack](analysis.json), [review](review.md).