ROAS, CAC and LTV Explained: The Marketing Metrics That Actually Matter

Dashboards are full of numbers, but only a few decide whether marketing is making money. Here are the metrics I use to judge every campaign.

ROAS: return on ad spend

Revenue from ads divided by ad spend. A 4x ROAS means AED 4 in revenue for every AED 1 spent. Useful for comparing campaigns, but dangerous alone because it ignores margins, returns and repeat purchases.

CAC: customer acquisition cost

Total sales and marketing cost divided by new customers acquired. Include agency fees, tools and content, not just media, to see the real cost.

LTV: customer lifetime value

The gross profit a customer generates over their relationship with you. Subscription businesses and repeat-purchase brands can afford higher CAC because LTV is higher.

The LTV to CAC ratio

A common rule of thumb is to aim for LTV of roughly three times CAC. Much lower and growth burns cash; much higher and you may be under-investing in growth.

MER: marketing efficiency ratio

Total revenue divided by total marketing spend. It cuts through attribution arguments between platforms that all claim credit for the same sale.

Contribution margin

Revenue minus product costs, fees, shipping and marketing. This is the number that tells you if growth is actually profitable.

Putting it together

• Use ROAS and CPA to optimise inside platforms
• Use MER and contribution margin to judge the overall business
• Use LTV to CAC to decide how aggressively to grow

A note on attribution

Every platform tends to over-credit itself. Combine platform data with your own analytics, post-purchase surveys asking "how did you hear about us?" and simple holdout tests to understand what is really driving sales.

Worked example

Imagine an online store selling a product for AED 200 with a gross margin of 50%, so each sale earns AED 100 before marketing.

• If ads drive sales at a ROAS of 4x, each AED 50 of ad spend produces AED 200 revenue, leaving AED 50 contribution per sale
• If ROAS falls to 2x, AED 100 of ad spend produces AED 200 revenue, leaving zero contribution
• If customers buy three times a year on average, LTV in gross profit is AED 300, so even a 2x first-purchase ROAS may be acceptable if retention is strong

The same ROAS can be excellent or disastrous depending on margin and repeat purchase behaviour.

Payback period

CAC payback is how long it takes for a customer's gross profit to repay the cost of acquiring them. Short payback periods protect cash flow, which matters for small businesses. Subscription and education businesses often track this closely.

Cohort analysis

Group customers by the month they were acquired and track their revenue over time. Cohorts reveal whether newer customers are as valuable as older ones, which channels bring loyal customers and whether retention efforts are working.

Leading versus lagging indicators

Revenue and profit are lagging indicators; they tell you what already happened. Leading indicators such as click-through rate, landing page conversion rate, lead quality and demo attendance warn you earlier. A good dashboard has both.

Building a simple marketing dashboard

• Spend, revenue and MER for the business overall
• CAC and ROAS by channel
• Conversion rates at each funnel step
• LTV and repeat purchase rate by cohort
• Brand signals: branded search and direct traffic

Review it weekly for decisions and monthly for strategy.

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