git:20260517.d9709b3 to git:20260711.c346837

- description: "PPC financial calculator and modeling tool. CPA, ROAS, CPL calculations, break-even analysis, impression share opportunity sizing, budget forecasting, LTV:CAC ratio analysis, and MER (Marketing Efficiency Ratio) assessment. Requires zero API access. Works with pasted data from exports. Use when user says PPC math, ad calculator, break-even, budget forecast, ROAS calculator, CPA calculator, impression share, LTV CAC, or MER."

- user-invokable: false

- tested_date: 2026-05-17

- tested_with: claude-code v2.x

- # PPC Financial Calculator & Modeling

-

- <!-- Created: 2026-04-13 | v1.5 -->

- <!-- Source: itallstartedwithaidea/google-ads-skills (PPC math concept) -->

-

- ## Process

-

- 1. Ask the user what calculation they need (or detect from context)

- 2. Collect required inputs (from pasted data, exports, or verbal description)

- 3. Perform calculations with clear formulas shown

- 4. Present results with interpretation and recommendations

- 5. Flag any concerning metrics or benchmarks

-

- ## Calculators

-

- ### 1. CPA Calculator

-

- ```

- CPA = Total Spend / Total Conversions

-

- Inputs needed:

- - Total ad spend (period)

- - Total conversions (same period)

-

- Output:

- - CPA with period context

- - CPA trend (if historical data provided)

- - Comparison to industry benchmark (from benchmarks.md)

- ```

-

- ### 2. ROAS Calculator

-

- ```

- ROAS = Revenue from Ads / Ad Spend

- ROAS% = (Revenue - Spend) / Spend × 100

-

- Inputs needed:

- - Total ad spend

- - Total revenue attributed to ads

-

- Output:

- - ROAS as ratio (e.g., 3.5x) and percentage (250%)

- - Break-even ROAS (based on margins if provided)

- - Comparison to platform benchmarks

- ```

-

- ### 3. Break-Even Analysis

-

- ```

- Break-Even CPA = Average Order Value × Profit Margin

- Break-Even ROAS = 1 / Profit Margin

-

- Inputs needed:

- - Average order value (AOV) OR average deal value

- - Profit margin (gross margin %)

- - Current CPA or ROAS

-

- Output:

- - Maximum profitable CPA

- - Minimum profitable ROAS

- - Current headroom (how far above/below break-even)

- - Recommendation: scale, maintain, or cut

- ```

-

- ### 4. Impression Share Opportunity

-

- ```

- Impression Share Lost (Budget) = opportunity from budget increase

- Impression Share Lost (Rank) = opportunity from bid/quality improvement

-

- Revenue Opportunity = Current Revenue × (1 / Current IS - 1)

-

- Inputs needed:

- - Current impression share %

- - IS lost to budget %

- - IS lost to rank %

- - Current spend and conversions

-

- Output:

- - Estimated additional conversions from full IS

- - Budget needed for full IS (estimated)

- - Priority: budget increase vs quality improvement

- ```

-

- ### 5. Budget Forecasting

-

- ```

- Projected Spend = Daily Budget × Days in Period

- Projected Conversions = Projected Spend / Historical CPA

- Projected Revenue = Projected Conversions × AOV

-

- Scaling scenarios:

- - Conservative: +20% budget → estimated impact

- - Moderate: +50% budget → estimated impact

- - Aggressive: +100% budget → estimated impact (with diminishing returns caveat)

-

- Inputs needed:

- - Current daily budget

- - Historical CPA (last 30 days)

- - Forecast period

- - AOV (if revenue projection needed)

-

- Output:

- - 3 scenarios with spend, conversions, revenue projections

- - Diminishing returns warning for aggressive scaling

- - 20% scaling rule reminder (never increase >20% at a time)

- ```

-

- ### 6. LTV:CAC Ratio

-

- ```

- CAC = Total Marketing Spend / New Customers Acquired

- LTV = Average Revenue per Customer × Average Customer Lifespan

- LTV:CAC Ratio = LTV / CAC

-

- Inputs needed:

- - Total marketing spend (all channels)

- - New customers acquired

- - Average revenue per customer (monthly or annual)

- - Average customer lifespan (months)

- - Optional: gross margin for unit economics

-

- Output:

- - LTV:CAC ratio with interpretation:

- - <1:1 = losing money on every customer

- - 1:1-2:1 = break-even to marginal

- - 3:1 = healthy (SaaS benchmark)

- - 5:1+ = may be under-investing in growth

- - Payback period: months to recover CAC

- - Recommendation based on ratio

- ```

-

- ### 7. MER (Marketing Efficiency Ratio)

-

- ```

- MER = Total Revenue / Total Marketing Spend

-

- Inputs needed:

- - Total business revenue (period)

- - Total marketing spend across ALL channels (same period)

-

- Output:

- - MER ratio (e.g., 5.0x)

- - Interpretation:

- - E-commerce: 3-5x typical, 8x+ excellent

- - SaaS: 5-10x typical (higher margins)

- - Local service: 3-8x typical

- - Comparison to business-type benchmark

- - Note: MER captures blended efficiency including organic, brand, and retention

- ```

-

- ### Incrementality & Advanced Measurement

-

- For advanced accounts evaluating cross-channel contribution:

- - **Meta Incremental Attribution** (launched April 2025): AI-powered holdout testing measuring real causal impact. Evaluate if budget exceeds $5K/month.

- - **Google Meridian** (2025): Open-source Marketing Mix Model for incrementality measurement across channels.

- - These tools complement PPC math calculations by measuring what would NOT have happened without the ad spend.

-

- For large accounts detecting small effects (5% MDE), multiply the 10% MDE sample by ~4x.

-

- ## Quick Formulas Reference

-

- | Metric | Formula |

- |--------|---------|

- | CPA | Spend / Conversions |

- | ROAS | Revenue / Spend |

- | CTR | Clicks / Impressions × 100 |

- | CVR | Conversions / Clicks × 100 |

- | CPC | Spend / Clicks |

- | CPM | (Spend / Impressions) × 1,000 |

- | CPL | Spend / Leads |

- | Break-Even CPA | AOV × Margin% |

- | Break-Even ROAS | 1 / Margin% |

- | LTV | ARPU × Avg Lifespan |

- | CAC | Total Marketing / New Customers |

- | MER | Total Revenue / Total Marketing |

- | Impression Share Opp | Revenue × (1/IS - 1) |

-

- ## Output Format

-

- ```

- ## PPC Financial Analysis

-

- ### [Calculator Name]

-

- **Inputs:**

- - [Listed inputs with values]

-

- **Results:**

- | Metric | Value | Benchmark | Status |

- |--------|-------|-----------|--------|

- | [Metric] | [Value] | [Benchmark] | PASS/WARNING/FAIL |

-

- **Interpretation:**

- [1-2 sentence analysis]

- **Recommendation:**

- [Actionable next step]

- ```

- ## Data to Request

- If the user doesn't provide enough data, ask for:

- - Platform and campaign type

- - Time period for analysis

- - Spend and conversion data

- - Revenue data (if ROAS/break-even needed)

- - Margin data (if break-even/LTV needed)

- - Business type (for benchmark comparison)