The short answer: choose a marketing consultant by testing four things — whether they diagnose before prescribing, whether they've worked at your stage (not just your industry), whether the engagement has a defined deliverable you can evaluate, and whether their pricing model matches the problem. A consultant who proposes solutions before understanding your funnel is selling a playbook, not consulting.
Most founders who've had a bad consulting engagement describe the same arc: an impressive first call, a confident proposal, six weeks of "discovery," and a deliverable that restates the problem they already knew they had. The expensive part isn't the invoice — it's the quarter you lost.
Almost all of those engagements were predictable at the vetting stage. Here's what to check.
1. Do they diagnose before they prescribe?
The single most reliable signal. A weak consultant arrives with the answer — usually whatever they sold the last client: more content, a rebrand, a new attribution tool. A strong one starts by asking how your funnel actually behaves: where leads come from, what converts, where pipeline stalls.
Test it on the first call. Describe your situation briefly and vaguely, then see what they do. If they start proposing solutions, they're pattern-matching to their playbook. If they start asking precise questions — what's your lead-to-opportunity rate? where does attribution break? — they're diagnosing. You want the second one. (This is the entire premise behind auditing a funnel layer by layer — the sequencing of the diagnosis matters more than the list of fixes.)
2. Have they worked at your stage — not just your industry?
Founders over-weight industry experience and under-weight stage experience. A consultant who's only worked with enterprise brands will prescribe enterprise machinery to your eight-person company. One who's only done early-startup scrappiness will under-build for a company doing $10M.
The problems at $1M, $5M, and $20M ARR are structurally different — what breaks, what's worth automating, what the founder should still be doing personally. Ask: "What's the closest company to ours — in revenue and team size — that you've worked with, and what did you change?" The specificity of the answer tells you everything.
3. Is the deliverable defined well enough to evaluate?
"Strategic guidance" is not a deliverable. Before signing, you should be able to state — in one sentence — what exists at the end of the engagement that doesn't exist now: a prioritised diagnosis, a rebuilt attribution model, a working nurture system, a positioning document tested against real customer interviews.
Two questions force this clarity: "What specifically will I have at the end?" and "How will we both know whether it was worth it?" A consultant who answers crisply has done this before. One who retreats to vagueness will retreat there mid-engagement too. Set this up properly and you also fix the other half of the problem — a good brief is what lets a good consultant start at full speed.
4. Does the pricing model match the problem?
Consultant pricing runs $150–$400/hour, $5,000–$50,000 per project, or $3,000–$15,000/month on retainer. The model matters as much as the number:
- A defined problem deserves project pricing. Fixed scope, fixed deliverable, fixed price.
- Be wary of a retainer pitched before you've worked together. Retainers suit an established relationship with a clear ongoing role — not a first engagement. Ask what's delivered each month and how you'd decide whether to continue.
- An audit or diagnostic ($1,500–$8,000) is the right-sized first step when you're not yet sure what's broken. It bounds your risk and shows you how the consultant thinks before you commit to anything larger.
5. Consultant, agency, or fractional CMO?
Worth thirty seconds of clarity, because they solve different problems. An agency executes a known playbook at volume. A consultant diagnoses and designs the system the execution should serve. A fractional CMO owns the function part-time inside your org chart. Hiring an agency when you need a diagnosis gets you more output into a broken funnel — the most common and most expensive mismatch.
The red flags, collected
- Proposes solutions on the first call, before seeing your data
- Can't name a client at your revenue stage
- Deliverables described as "guidance," "support," or "alignment"
- Pushes a retainer before any defined project
- Guarantees rankings, leads, or revenue numbers
- Won't explain their own attribution thinking — how they'd measure whether their work worked
Any one of these is a conversation. Two or more is a pass.
The vetting questions, all in one place
- What would you need to learn about our funnel before recommending anything?
- What's the closest company to ours — revenue and team size — you've worked with?
- What specifically will I have at the end of this engagement?
- How will we both know whether it was worth it?
- Why this pricing model for this problem?
- How do you measure whether your own work worked?
Where to start
If you want to see diagnostic thinking before committing to anything, that's what the Strategy Diagnostic is for — a structured audit of your marketing system, delivered as a written report with a prioritised plan, fixed at $1,500. It's deliberately scoped to be the test: you see exactly how I think, and you can act on the result with or without me. Background on the approach at marketing systems consulting.