Marketing contribution

Most founders know what they spend on marketing and what revenue they made. Far fewer can say whether the marketing paid for itself. Marketing Contribution answers that, per channel and blended.

What you enter

For each channel (Meta, Google, affiliates, email — whatever you actually run):

• Ad spend items — one row per line item within the channel, so you can separate prospecting from retargeting.
• Revenue — revenue attributed to that channel, monthly.
• Transactions — order or conversion count, monthly.

Shared costs sit outside any single channel: agency retainers, creative production, marketing salaries, tooling. They're excluded from per-channel ROAS but included in the blended numbers, which is what keeps the blended view honest.

Any cell accepts shorthand — 50k becomes 50,000.

What it calculates

Per channel:

• ROAS — revenue divided by ad spend. 4.0 means four dollars back for every dollar in.
• CPA — ad spend divided by transactions. Your cost to acquire one order.
• AOV — revenue divided by transactions. Average order value.

Blended, across everything including shared costs:

• MER (Marketing Efficiency Ratio) — total revenue divided by total ad spend. The single best number for "is marketing working?" Higher is better.
• ASR (Advertising-to-Sales Ratio) — ad spend as a share of revenue. Lower is better; it's MER inverted and it's the number a CFO will ask for.
• Contribution — revenue minus all marketing spend. If this is negative, you're buying revenue at a loss.

Unit economics assumptions

Three inputs at the top drive every profit figure in the tool:

• Gross margin % — pulled automatically from your P&L over the last twelve months, so the two tools agree. Type over it to use your own number; a link appears to switch back to the P&L figure. If your P&L has no cost of goods yet, this is where to start — without it, every "contribution" number in any tool is really just revenue minus marketing.
• Lifetime orders per customer — how many times an average customer buys. The default is 1, which is deliberately pessimistic: it assumes nobody ever comes back.
• Months between orders — how fast repeat purchases arrive, which sets the pace of CAC payback.

Contribution after cost of goods

Three tiles under the scorecard show gross profit, contribution after COGS, and contribution margin, alongside the revenue-based figure for comparison.

This distinction matters more than it sounds. A brand doing $8,000 of revenue on $3,000 of marketing looks like $5,000 of "contribution" on a revenue basis. At a 20% gross margin, the truth is $1,600 of gross profit against $3,000 of spend — a $1,400 loss. Physical-product businesses can run a long way on the flattering number before noticing.

Per-channel unit economics

Each channel shows a strip of metrics above its rows:

• ROAS — revenue ÷ ad spend, as before.
• CPA — ad spend ÷ orders.
• CAC — ad spend ÷ new customers. Fill in the New customers row to make this exact; without it the tool assumes every order came from a first-time buyer, which reads pessimistically and is labelled where it happens.
• LTV:CAC — gross-profit lifetime value ÷ CAC. Above 3× is the conventional floor for a healthy channel. Note this uses gross profit, not revenue — a 4× revenue-based ratio on a 25%-margin product is really 1×.
• CAC payback — months of gross profit needed to earn back the acquisition cost. Under 12 months is a common ceiling for a business funding its own growth; a channel can look efficient on ROAS and still starve you of cash if payback is two years out.
• Contribution — that channel's gross profit minus its ad spend.

Per-channel targets

Click Targets on any channel to set a minimum ROAS and a maximum CPA. Those metrics then grade green, amber, or red against your own numbers rather than a generic benchmark. Leave a field blank to track a metric without grading it. Blended MER and ASR goals still live in the scorecard.

Budget planner

The planner at the bottom answers the question the rest of the tool can't: what happens if I move money?

Each channel shows its current average monthly spend and an editable planned figure. Change two numbers — drop Meta by $10k, raise Google by $10k — and the planner projects orders, revenue, and contribution for each channel at its own current CPA and average order value, then shows monthly revenue, contribution after COGS, and blended MER before and after.

What it assumes. CPA is held flat. In reality, doubling spend on a channel usually raises its CPA, so treat the output as the optimistic case and a starting point for a conversation — not a forecast. Channels with no spend history show —, because there's no CPA to project from.

Your plan is saved, so you can come back to it. Reset returns every channel to its current spend.

Goals and the scorecard

Set your MER and ASR goals in the scorecard at the top. Each metric is then colour-coded: green when you're at or better than goal, amber when you're close, red when you're not. Set goals you'd genuinely be happy with rather than ones you're already hitting.

Multiple years

Use the year tabs to keep a separate year of data, and Add year to start a new one — it copies your channel structure so you don't rebuild it. Year-over-year comparison is where this tool starts earning its keep.

Exporting

Export CSV produces every channel's spend, revenue, transactions, new customers, and KPIs plus the blended roll-up for the active year — including gross profit, contribution after COGS, and contribution margin — one row per line item and one column per month.

Reading it well

• A channel with great ROAS and tiny spend isn't a win — it's an under-invested opportunity. Look at contribution in dollars, not just ratios.
• Blended MER is the truth; per-channel ROAS is the diagnosis. Attribution overlaps between channels, so channel numbers usually sum to more than reality.
• Empty months are shown as — rather than zero, so a month you haven't filled in doesn't drag your averages down.