How to Choose a Performance Marketing Agency: 10 Critical Questions to Ask Before Signing
Most failed agency engagements weren't doomed by bad work. They were doomed at the hire — the wrong agency for the wrong stage of business, sold by a strong sales process that hid a weak delivery process.
The good news: this is the easiest part of the relationship to get right, because the same five or six questions reveal almost everything. Below is the framework we'd use to vet a performance marketing agency in 2026 if we were the client.
Why agency hires go wrong
Three patterns account for most failures:
- Sales team ≠ delivery team. The senior strategist you meet on the pitch call disappears after contract signing, replaced by a junior account manager.
- Wrong-stage match. A boutique that scaled DTC brands to $5M tries to take on a $40M B2B SaaS account and applies the wrong playbook.
- No real attribution. The agency reports last-click revenue from Google Ads as if it's incremental, when most of those customers would have found you anyway through SEO.
The questions below are designed to expose all three before you sign.
The 10 questions
1. Who specifically will work on my account, and what's their experience?
You want names, LinkedIn profiles, and years of relevant experience. The senior strategist on the pitch call should also be on the weekly account call. If they aren't, you're hiring a junior with a senior badge.
Green flag: "Your dedicated strategist will be [name], 7 years running paid acquisition for B2B SaaS, formerly at [recognizable company]. They'll be on every weekly call."
Red flag: "We have a team-based approach with multiple specialists supporting your account." (Translation: nobody is really accountable.)
2. Show me a case study from a business in my industry and stage
Not just any case study. One from a business with a similar revenue, similar ACV, similar sales cycle. An agency that scaled an ecommerce brand to $10M ARR has a very different toolkit than one that needs to drive $50K-ACV B2B SaaS demos.
Green flag: Multiple case studies with named clients, specific metrics (CAC dropped from X to Y, ROAS scaled to 4.2×), and the exact tactics used.
Red flag: Anonymous case studies, vague metrics ("we 3x'd their pipeline"), or case studies from industries totally different from yours.
3. What's your attribution philosophy?
The agency's answer here tells you whether they're sophisticated or just running ads. A serious answer mentions multi-touch attribution, the limits of platform-reported numbers, server-side tracking, post-purchase surveys, or media mix modeling.
Green flag: "We blend platform-reported ROAS with post-purchase surveys and a quarterly MMM check, because last-click overcounts paid by ~30% in most B2B sales cycles."
Red flag: "We pull ROAS straight from Google Ads and Meta and report it to you."
4. What's your reporting cadence, and can I see a sample report?
Ask for a real (redacted) report from an active client. The format tells you what they actually optimize for. If the report is 30 pages of vanity metrics with no clear "what we changed this week and why," that's how they'll think about your account too.
Green flag: Clean weekly report with: spend, leads, CAC, ROAS, what we changed, what we'll change next.
Red flag: 40-slide monthly reports full of impressions, clicks, and engagement metrics.
5. What's the first 90 days look like?
A good agency has a structured onboarding: audit, attribution setup, baseline measurement, then optimization. A bad agency starts running ads on day three.
Green flag: "Weeks 1-2: audit and tracking setup. Weeks 3-6: launch and learning phase. Weeks 7-12: optimization and scaling. We expect first meaningful improvements by week 8."
Red flag: "We'll have ads live in 48 hours."
6. How do you decide what to scale and what to kill?
Their decision framework reveals whether they think in systems or in tactics. A serious agency will talk about statistical significance, payback periods, and cohort-level economics, not "we'll let it run another week and see."
Green flag: "We use a rolling 14-day CAC + ROAS threshold per campaign, weighted by spend volume. If a campaign breaches the threshold for 7 consecutive days, we pause it."
Red flag: Vague answers about "monitoring performance" without thresholds or rules.
7. What's your contract structure, and what's the exit?
Watch for: 12-month minimums, auto-renewal clauses, IP ownership of the assets they build, and what happens to your ad accounts when the relationship ends. You should own every ad account, asset, and creative — not the agency.
Green flag: Month-to-month or quarterly terms with a 30-day exit notice, you own all accounts and assets.
Red flag: 12-month auto-renew, agency-owned ad accounts.
8. What do you specifically not do?
The best agencies have a clear refusal pattern. "We don't do SEO" or "we don't take retainers under $5K" is a sign of focus. Agencies that say yes to everything are usually mediocre at most of it.
Green flag: "We don't do brand-only campaigns, we don't take on businesses below $1M ARR, and we don't run paid social without a CRO partner."
Red flag: "We do everything — SEO, paid, social, content, email, web design, and influencer marketing."
9. References — can I talk to three current and three former clients?
Current clients tell you what working with the agency is actually like. Former clients tell you why people leave. Always insist on both, and call at least one of each.
Green flag: Agency offers up references without hesitation.
Red flag: Agency offers only "happy" references, no formers, or claims to have a non-disclosure that prevents references.
10. What's the smallest engagement that makes sense to try this?
Strong agencies offer a paid pilot — a 60- or 90-day project that lets you evaluate them before committing to a retainer. If they refuse any sub-12-month engagement, they're optimizing for the sales win, not the fit.
Green flag: "Our standard is a 90-day paid pilot at $5K-$10K total, after which both sides decide if a retainer makes sense."
Red flag: "Our minimum is a 12-month retainer." (For a relationship neither side has tested yet? No.)
Three red flags that should end the conversation
- They guarantee specific results. "We'll get you 50 leads / month" without seeing your funnel is sales theater. Real agencies set expectations based on diagnosis, not deck slides.
- They want you to give them your ad account login before signing. Risk-free agencies don't need account access during the sales process; they need contract signature first.
- Their senior people refuse to be on calls. If you're paying $5K+ / month and can only talk to junior account managers, you're paying senior rates for junior work.
The three-call vetting process
Don't decide after one call. Run every shortlisted agency through:
- Call 1 — Discovery (60 min). They learn about you, you screen for basic fit.
- Call 2 — Strategy (60 min). They present a thesis on your account: what they'd test in the first 90 days, what attribution looks like, what success means.
- Call 3 — References (45 min). You talk to two current clients and one former. Ask: "What's the agency bad at?"
Most agencies disqualify themselves between call 1 and call 2.
FAQ
How long should I take to choose a performance marketing agency? Most thorough hires take 3-6 weeks: 1-2 weeks of shortlisting and intro calls, 1-2 weeks of strategy presentations, then 1 week of reference checks and contract review.
Should I hire a generalist agency or a specialist? For most US businesses under $5M revenue, a generalist performance marketing agency with strong attribution skills is the better fit. Above $5M, specialist agencies per channel often outperform generalists.
Do I need to commit to a 12-month contract? No. Strong agencies offer quarterly or month-to-month terms. 12-month auto-renew is an agency-friendly clause that protects them from being fired for poor performance — a serious red flag.
What if the agency wants to run a paid pilot before a retainer? Take it. A 60- or 90-day paid pilot is the lowest-risk way to evaluate fit before committing to a long engagement.
Who should own the ad accounts? You should own every ad account, pixel, tag, GA4 property, and ad creative. If the agency insists on owning them, you're locked in — that's a deal-breaker.
Adscular runs every engagement on a 60-day paid pilot before any retainer commitment. Book your free growth audit — we'll show you what the first 90 days would look like, no obligation.