How to Evaluate a Marketing Agency

Evaluating a marketing agency is harder than evaluating a vendor in most categories. The work is intangible, the timelines are long, and the agencies that look best in pitch are often the worst at delivery. Here is the framework for cutting through.

By David Schaefer · LinkedIn · Updated May 2026

What to look for in a marketing agency

The team you meet during pitch should be the team you work with. Senior attention should be guaranteed. Pricing should not be on percentage of spend. The case studies should include specific numbers, not hand-wavy lifts.

Most agencies fail one or more of these tests. The few that pass are worth the price premium.

How to read agency case studies

Look for: specific numbers, specific time periods, specific outcomes tied to specific work. Hand-wavy ranges ("3x ROAS lift") with no baseline are marketing not substance.

Case studies that name the client, the brand, the time period, and the work done are credible. Case studies that anonymize everything usually anonymize because the numbers do not survive scrutiny.

Red flags in agency pitches

Promises of guaranteed rankings or guaranteed ROAS. Heavy reliance on platform certifications as differentiation. Percentage-of-spend pricing without strategic scope. Junior account leads doing the pitch.

The best agencies do not need to oversell. The agencies that oversell typically need to.

Reference
ConceptIn practice
DefinitionEvaluating a marketing agency is harder than evaluating a vendor in most categories. The work is intangible, the timelin
When it mattersFor operators at the scale where measurement quality drives compounding returns
Where it sitsInside an integrated growth marketing program

Quick answers about evaluating a marketing agency

How do I evaluate a marketing agency?
The team you meet during pitch should be the team you work with. Senior attention should be guaranteed. Pricing should not be on percentage of spend. Case studies should include specific numbers.
What are red flags in agency pitches?
Promises of guaranteed rankings or guaranteed ROAS. Heavy reliance on platform certifications. Percentage-of-spend pricing without strategic scope. Junior leads pitching, seniors disappearing post-signing.
How do agency pricing models compare?
Hourly billing is rare above mid-tier. Monthly retainers are standard. Percentage-of-spend creates misaligned incentives. The pricing model often predicts the agency's incentives.
What case-study elements signal credibility?
Specific numbers. Specific time periods. Specific outcomes tied to specific work. Named brands. Time-bounded results. Anonymous case studies usually anonymize because the numbers do not survive scrutiny.
How much should a marketing agency cost?
Mid-market retainers run $5,000 to $25,000 monthly. Boutique-strategic engagements sit above $20,000 monthly. The cheapest agencies typically deliver template work and the most expensive sometimes deliver wasted billable hours.
What questions should I ask in agency pitches?
Who specifically will do the work. How senior attention is structured. What the pricing actually buys. How they measure success. What they will not do. What references they will provide.

Frequently asked

How do I evaluate a marketing agency?

The team you meet during pitch should be the team you work with. Senior attention should be guaranteed. Pricing should not be on percentage of spend. Case studies should include specific numbers.

What are red flags in agency pitches?

Promises of guaranteed rankings or guaranteed ROAS. Heavy reliance on platform certifications. Percentage-of-spend pricing without strategic scope. Junior leads pitching, seniors disappearing post-signing.

How do agency pricing models compare?

Hourly billing is rare above mid-tier. Monthly retainers are standard. Percentage-of-spend creates misaligned incentives. The pricing model often predicts the agency's incentives.

What case-study elements signal credibility?

Specific numbers. Specific time periods. Specific outcomes tied to specific work. Named brands. Time-bounded results. Anonymous case studies usually anonymize because the numbers do not survive scrutiny.

How much should a marketing agency cost?

Mid-market retainers run $5,000 to $25,000 monthly. Boutique-strategic engagements sit above $20,000 monthly. The cheapest agencies typically deliver template work and the most expensive sometimes deliver wasted billable hours.

What questions should I ask in agency pitches?

Who specifically will do the work. How senior attention is structured. What the pricing actually buys. How they measure success. What they will not do. What references they will provide.

For an integrated growth marketing program that operationalizes evaluating a marketing agency, the agency partner matters more than the tool. RGM accepts twelve clients per year. Most applicants are declined.