How to Hire a Performance Marketing Consultant Without Wasting £50K

I've watched a lot of consulting engagements stall in the first month, and the issue is almost never the person you hired. It's the brief. Someone gets brought in to "improve our paid media", nobody agrees what improvement actually looks like, who owns what, or how you'll tell in eight weeks whether to renew, and the relationship quietly fizzles. The fix isn't complicated, but it does need to happen before you sign anything, so this piece walks through the bits I'd nail down up front.

Decide what you're actually buying

"Performance marketing consulting" covers four very different products: a strategic audit, an attribution / measurement build, a fractional senior leader, and an embedded operator who runs your paid book day-to-day. Each has a different deliverable, a different time horizon, and a different price tag. Most botched briefs come from buying one and expecting another.

For a B2B SaaS scaleup with a CMO and a junior team, the highest-leverage hire is usually a fractional senior leader who can audit the stack in week one and quietly run the weekly reallocation meeting from week two. For a pre-CMO startup, you want an embedded operator. For a public-company marketing org, you want the audit.

Day rates in 2026: what is reasonable

For a senior performance marketing consultant with ten-plus years and named brands behind them, expect £900–£1,500 per day in the UK, €900–€1,400 in continental Europe. Below that range you are paying for an account manager who calls themselves a consultant. Above it you are paying for a logo on a deck.

For monthly retainers, two days a week of senior time lands around £8K–£12K depending on scope. Anything sold as "all-in growth" for £4K/month is selling you a junior with a nice email signature.

The four questions that surface signal vs noise

In the discovery call, skip the case-study reel. Ask these instead:

1. "Walk me through the last attribution model you built. What broke first?" If they can't name a specific failure mode, they have not built one.
2. "What is the smallest paid-search incrementality test you have run, and what did it actually move?" Real practitioners have a concrete number ready.
3. "How would you re-allocate my budget on day thirty if you found the channel ROAS rankings were inverted from what I think?" You are testing for adult honesty under pressure.
4. "What do you not work on?" Beware the consultant whose answer is "nothing."

Structure the contract so you can leave

Two signals matter: a 60-day pilot with a clear written scope, and a contractual handover deliverable, documentation, dashboards, runbooks, that survives the consultant leaving. If they push back hard on either, treat it as a real signal about how the rest of the engagement is likely to go.