POAS Decision Model
A structured framework for every Google Ads investment decision. When to scale, when to cut, when to kill - and the exact logic behind each call.
Last updated: April 2026
How do you decide when to scale or cut Google Ads spend?
TLDR: Scale = POAS headroom + stable CPA + capacity. Cut = negative margin for 14+ days. Every SKU gets a role.
Use the POAS Decision Model: assign every SKU a commercial role (Scale, Protect, Recover, Pause) based on its contribution margin and 30-day POAS. Scale when POAS exceeds breakeven by 30%+, marginal CPA is stable, and you have fulfilment capacity. Cut when contribution margin is negative for 14+ days. The model removes emotion from budget decisions and replaces it with commercial logic.
The Decision Tree
Run every SKU through this sequence. Each question has a binary outcome that determines the next action.
Is this SKU's contribution margin positive after COGS, shipping, returns, and fees?
Continue to next question
PAUSE - stop advertising this SKU until margin is fixed at the product level
Is POAS above your fully-loaded breakeven threshold?
Continue to next question
RECOVER - reduce bids 20-30% and set a 30-day improvement window
Is marginal CPA stable or falling as you increase spend?
Continue to next question
PROTECT - hold current spend level. You've hit diminishing returns.
Do you have operational capacity to fulfil incremental orders without cost inflation?
SCALE - increase bids 10-20% and monitor weekly
PROTECT - demand exceeds fulfilment capacity. Scale when operations are ready.
The Four SKU Roles
Every product in your catalogue gets one of four roles. The role determines its bid strategy, budget allocation, and review cadence.
Scale
Criteria
POAS > 2.0x, positive contribution margin, stable or falling marginal CPA
Action
Increase bids 10-20%, expand match types, test new audiences. Monitor marginal CPA weekly.
Protect
Criteria
POAS 1.3-2.0x, healthy margin, consistent volume
Action
Maintain current bids. Optimise for efficiency, not growth. Focus on feed quality and negative keywords.
Recover
Criteria
POAS 0.8-1.3x, below breakeven but with turnaround potential
Action
Reduce bids 20-30%, tighten targeting, improve product page conversion rate. 30-day review window.
Pause
Criteria
POAS < 0.8x for 14+ days, negative contribution margin, no strategic value
Action
Stop advertising immediately. Reallocate budget to Scale and Protect SKUs. Re-evaluate when margin changes.
Contribution Margin: The Foundation
Every decision in this model depends on honest contribution margin. Most brands use gross margin - which overstates profitability by ignoring post-sale costs.
Contribution Margin =
Order Total
− VAT
− COGS (landed cost, not just supplier price)
− Shipping (actual, not flat rate)
− Returns Risk (category return rate × order value)
− Payment Processing Fees
− Platform Fees (Shopify, marketplace commissions)
POAS = Contribution Margin ÷ Ad Spend
If your POAS calculation uses gross margin instead of contribution margin, every role assignment in this model will be wrong. See our full breakdown.
When to Scale: The Three-Gate Test
Scaling feels like progress. But scaling without checking all three gates turns profitable campaigns into margin-destroying ones.
Gate 1: POAS Headroom
POAS must exceed your breakeven threshold by at least 30%. If breakeven is 1.2x POAS, you need 1.56x before scaling. This buffer absorbs the efficiency loss that always accompanies spend increases.
Gate 2: Marginal CPA Stability
Plot your CPA against spend over the last 30 days. If marginal CPA rises faster than conversion volume, you're past the inflection point. More spend won't generate proportionally more profit.
Gate 3: Operational Capacity
Can your warehouse, customer service, and supply chain handle 20% more orders without cost inflation? If scaling triggers expedited shipping, overtime, or stockouts, the incremental margin evaporates.
When to Cut: The Rules
Contribution margin per order is negative for 14+ consecutive days
Marginal CPA exceeds the profit from the next incremental conversion
Stock levels can't support demand without fulfilment cost inflation
Seasonal demand has peaked and efficiency is declining week-over-week
Product has been recalled, discontinued, or has quality issues driving returns above 25%
Cutting isn't failure. It's capital reallocation. Every pound removed from a Pause SKU and redirected to a Scale SKU compounds the portfolio's profitability.
How to Implement the POAS Decision Model
A step-by-step guide to implementing profit-led decision-making across your Google Ads account using SKU roles and contribution margin.
- 1
Calculate contribution margin
Calculate true contribution margin for every SKU: Revenue − COGS − Shipping − Returns Risk − Payment Fees − VAT
- 2
Set POAS breakeven
Set your POAS breakeven threshold: the point where ad spend equals contribution margin
- 3
Assign SKU roles
Assign each SKU a role (Scale, Protect, Recover, Pause) based on 30-day POAS and margin data
- 4
Set bid strategies per role
Set bid strategies per role: aggressive targets for Scale, conservative for Protect, reduced for Recover, zero for Pause
- 5
Monthly role reassignment
Review and reassign roles monthly - margins change with seasons, stock levels, and supplier costs
- 6
Measure portfolio POAS
Measure portfolio-level POAS weekly - individual SKU decisions should improve the aggregate
Frequently Asked Questions
What is a POAS decision model?
A POAS decision model is a structured framework for making advertising investment decisions based on profit rather than revenue. It maps every SKU to a commercial role (Scale, Protect, Recover, Pause) based on its contribution margin, then sets different bidding strategies and budget rules for each role. The model ensures ad spend flows to profitable products and away from margin-destroying ones.
How do you decide when to scale Google Ads spend?
Scale when three conditions are met simultaneously: (1) POAS exceeds your breakeven threshold by at least 30%, (2) marginal CPA is not rising faster than conversion volume, and (3) you have operational capacity to fulfil incremental orders without margin erosion from expedited shipping or overtime. If any condition fails, scaling destroys margin even if ROAS looks healthy.
When should you cut Google Ads spend?
Cut spend when contribution margin per order falls below your fully-loaded breakeven point for 14+ consecutive days, when marginal CPA exceeds the profit from the next incremental conversion, or when stock levels can't support the demand without fulfilment cost inflation. The decision is mathematical, not emotional.
What are SKU roles in Google Ads management?
SKU roles assign each product a commercial function in your advertising portfolio: Scale (high margin, high volume - invest aggressively), Protect (high margin, moderate volume - maintain position), Recover (low margin, high volume - restructure or reduce), and Pause (negative contribution - stop advertising). Roles change monthly based on live margin data.
How is POAS different from ROAS for decision-making?
ROAS tells you revenue per ad pound but ignores costs, so a 4x ROAS on a 20% margin product actually loses money after fulfilment. POAS uses gross profit instead of revenue, making every bidding decision commercially honest. A 1.5x POAS means you're making £1.50 in gross profit for every £1 in ad spend - a genuinely profitable outcome regardless of margin structure.