"The agency works well" is not a metric. To understand whether a marketing agency brings real value to the business, you need to agree on specific KPIs in advance and regularly check them, rather than relying on general impressions from reports.
ROMI — Return on Marketing Investment
The formula is simple: (marketing revenue − marketing expenses) / marketing expenses × 100%. High ROMI shows that the money invested is actually returning with profit, not just being spent on reach. This is the first metric you should ask any marketing agency about.
CAC — Customer Acquisition Cost
CAC reflects how much a company spends on average to acquire one new customer through a specific channel. If an agency can't state the CAC for its campaigns, it probably doesn't connect its work with actual sales.
LTV — Lifetime Value
LTV shows the profit a customer brings to the company over the entire relationship period — not from a single purchase. Comparing CAC and LTV is one of the most honest ways to understand whether an acquisition channel pays off in principle, not just in the moment.
CTR and engagement metrics
CTR (the share of those who clicked out of those who saw the ad) and engagement metrics are important as an early indicator — they show whether the creative and audience targeting work, even before sales statistics accumulate.
It's recommended to choose 3–5 key metrics that accurately reflect current business objectives — rather than tracking everything at once.
End-to-end analytics — the metric that unites the rest
Full-scale evaluation requires linking several systems: web analytics — for traffic and behavior, advertising accounts — for spend and impressions, CRM — for leads and sales, and end-to-end analytics that connects marketing costs with actual revenue. An agency that offers to set up such a connection usually understands business more deeply than one that reports only on reach.
How to use these KPIs in practice
Define goals in advance, choose 3–5 metrics for them, and only then start measuring performance — not the other way around. The same set of 12 KPIs doesn't fit both launching a new product and scaling an already profitable funnel: metric priorities should change along with business objectives.
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