Marketing Efficiency
by
Efficiency targets for ecommerce teams: set a MER target per channel from the contribution each one actually delivers, not one blended number.
Blended marketing efficiency ratio gets set as one number for the whole business, which forces every channel to hit the same target regardless of what it sells or what it costs to fulfill. A channel driving high margin products can be profitable at a far lower ratio than one driving thin margin volume, and holding both to the same line over-spends on one and starves the other. The right target is different per channel and it moves as the product mix moves. This skill sets a MER target per channel from the contribution each one actually delivers.
What It Does
- Computes contribution per channel after product cost, returns and shipping.
- Derives the efficiency ratio each channel needs to clear your margin floor.
- Accounts for the product mix each channel actually drives.
- Adjusts for the customers a channel acquires versus the orders it harvests.
- Tests the targets against the volume the business needs next month.
- Sets the target per channel, with the contribution it protects.
Use Cases
- Stop holding every channel to one efficiency number.
- Give a high margin channel room to spend more.
- Tighten a channel driving thin margin volume.
- Set next month's targets from the mix rather than from last month.
Example Session
What should each channel's efficiency target be next month?
One blended target is wrong for all four. Here is the target each one needs.
- Channel | Product mix margin | Current MER | Required MER | Verdict
- Paid search, non-brand | 58% | 3.1 | 2.4 | Room to spend more
- Paid social, prospecting | 34% | 3.0 | 4.1 | Spending too loosely
- Shopping feed | 26% | 3.4 | 5.3 | Well below target
- Email and lifecycle | 61% | 12.0 | 2.3 | No constraint
The shopping feed drives your thinnest margin products and needs a 5.3 to clear the same floor that non-brand search clears at 2.4. Holding both to a blended 3.0 means the feed has been losing money all year while non-brand search has been throttled. That single change is worth more than any bidding adjustment in either channel.
Why This Beats Prompting It Yourself
One Blended Target vs A Target Per Channel: The Hidden Risk
A generic prompt recommends a blended MER target because that is how the metric is usually discussed. A blended number is an average of channels selling different products at different margins into different fulfillment costs. Holding all of them to it guarantees over-spending in the thin ones and under-spending in the rich ones, simultaneously.
When You Still Need The Mix To Set The Target
The target moves when the product mix moves, which happens every time a promotion runs or a category sells through. This skill recomputes from the mix each channel is currently driving rather than from last quarter's, which is why the shopping feed's number is 5.3 this month and was something else before.
Known Limitations
Channel-level contribution inherits your attribution, so channels that are poorly attributed carry that uncertainty into their target and the output says which. The acquisition-versus-harvest adjustment is directional rather than a substitute for a holdout test. It sets the targets and does not change budgets or bids.
Install It
- Download the ZIP.
It is free and there is no account to create. - Unzip it into your agent's skills folder.
Claude Code reads ~/.claude/skills/, which is hidden by default: the command in the folder block opens it. Other agents scan their own directory, so drop the same folder there instead. - Ask your agent to use it.
Restart the agent if it was already running, then it picks the skill up with no config.
skills folder
Copy
~/.claude/skills/marketing-efficiency/
SKILL.md
references/mer-model.md
targets/
# one file per month, with the target per channel
# macOS: create the folder and open it in Finder
mkdir -p ~/.claude/skills && open ~/.claude/skills
# Windows: paste in the Explorer address bar
%USERPROFILE%\.claude\skills\Frequently asked questions
How is this different from a blended MER target?
A blended target treats every channel as though it sells the same products at the same margin into the same fulfillment cost. This computes what each channel actually delivers in contribution and derives the ratio it needs to clear your floor, which differs by more than most teams expect.
Which agents does the skill run in?
Any agent that supports the open SKILL.md format: Claude Code, Cursor, Codex CLI, GitHub Copilot, Gemini CLI, Manus, Grok and others load it unmodified. The format is portable, the location is not. Each agent scans its own skills directory, so you drop the same folder into whichever one yours uses. There is no config file to edit and no API key to provision.
What does it need connected to work?
Spend and revenue per channel, order lines so the product mix per channel is visible, product margin, returns and shipping cost. New versus returning customer data improves the acquisition adjustment.
Why does the shopping feed need such a high target?
Because it drives your thinnest margin products. At 26% product margin, a dollar of revenue leaves far less to cover the ad spend, so the ratio has to be higher to reach the same contribution. The number is not a judgment about the channel, it is arithmetic about what it sells.
How often should targets change?
Monthly, or whenever the product mix shifts materially. A promotion that pushes volume into a different margin band changes what every channel touching it needs to clear, and holding last quarter's target through that is how a good month produces a bad margin.
What is included with the skill?
The skill itself, the MER model reference, the monthly target format, and the mix adjustment rules. It is free and security scanned. We re-publish the ZIP when the model changes, so download it again if your targets start shifting.
An MER target is only meaningful on one definition of revenue.
Polar puts every channel on the same net revenue and blended CAC, so the target you set per channel stays comparable through the month.
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