MK-064 | Customer acquisition cost ceiling calculation
For a regular chat, upload packs/mk-064.md. It includes the shared rules, this method, and required references
Purpose
This skill delivers: An estimate based on average order value, gross margin, and the affordable allocation
Recalculability does not mean the data is complete; break-even points and cost ceilings apply only under the stated assumptions
Required inputs
Raw inputs: specified Target CPA and valid-order definition; an approved simplified estimate requires average order value, gross-margin rate, ad-allocation fraction and covered cost items with period/currency
Method
- Use the case-specified Target CPA with source, cost scope and valid-order definition. Otherwise find approved estimating assumptions; 30% is a teaching example, not a default
- For an approved simplified estimate, Target CPA equals average order value times gross-margin rate times acceptable ad-allocation fraction. Revenue target divided by average order value is target order volume, not part of per-order CPA
- Identify costs already deducted in the margin and the portion being allocated, counting ad costs once. Product margin alone gives a partial estimate with actual missing costs; full affordability needs the approved profit calculation rather than treating margin as net profit
- Check nonnegative amounts, fractions from 0 to 1 and consistent definitions; repair invalid input. Zero/negative available contribution provides no positive ad allowance rather than a profitable zero-cost recommendation. Retain an explicitly approved zero Target CPA as the stated goal
- Deliver inputs, units, source, substitution and result. Recompute with changed order value, costs or approved allocation. New-customer CAC uses its own customer count and specified expenses, not a renamed order CPA
Calculations and interpretation
Hypothetical approved estimate: average order value 1,200, margin 60% and allocation 30% give Target CPA = 1,200 × 0.60 × 0.30 = 216 per valid order. An approved 20% allocation gives 144. Without a fraction, report order margin 720 and an unset allocation rather than filling 30%
Decision rules authored by ThinkWithBlack on 2026-10-14; original course sources are retained below
Required output fields
| Order | Field | How to complete |
|---|---|---|
| 1 | Input variable | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 2 | Value | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 3 | Unit and definition | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 4 | Source | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 5 | Formula | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 6 | Result | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
| 7 | Limitations | Use source evidence, an intermediate method result, or an explicit unknown; do not invent information |
Verification cases
MK-064-A1 | Explicit approved Target CPA=0
Expected: Retain the stated target; no denominator-zero rejection
MK-064-A2 | Only AOV1200 and margin60%, no allocation ratio
Expected: Retain margin720 and the missing ratio, without defaulting to30%
Method sources
Source file: Meta廣告學程 104 廣告的數據決策
Location: CPA
Source basis: extracted from course materials
Source URL: https://docs.google.com/presentation/d/16FiqnSxBs-gSDxsxUBNhWdUX5vZrIWoZPGangj_f_Pk/edit
English translation of source excerpt:
Reasonable CPA
