Choosing a PPC Agency: The Criteria Most RFPs Miss

The Criteria Most CMOs Use Are the Wrong Starting Point

The dominant pattern in PPC agency selection has not changed in a decade. Procurement teams and consultants push the same set of criteria: sector experience, platform certifications, team size, client references, reporting quality. These criteria are not wrong. They are simply insufficient, because every serious finalist meets them. They screen for the bottom 30% of the market, not for the top 10%.

What actually differentiates a good agency from a mediocre one becomes visible only after six months, when the first cycle of results comes back and the question stops being “what did the dashboard show” and starts being “did this campaign actually drive incremental revenue, and how do we know”. At that point, the standard criteria are silent. The agency points to its own reports, the reports are generated from the same platforms the agency buys from, and the CMO has no way to distinguish genuine performance from self-attribution.

When evaluating a PPC agency, the criteria that survive that moment are the ones that matter. Measurement independence, profit literacy and exit terms are structural. They determine whether the engagement produces decision-grade insight or a recurring monthly invoice for activity that may or may not be working. Everything else is commercial hygiene.

The Five Structural Criteria That Actually Predict Outcomes

Below the standard hygiene layer, five criteria separate the agencies that earn their retainer from the agencies that bill it. These are the structural axes of PPC agency selection, in order of importance:

• • Measurement independence. Does the agency run incrementality testing or geo holdouts to verify its own contribution, or does it rely exclusively on the ROAS reported by Google Ads and Meta? If the measurement comes from the same platforms the agency buys media on, the agency is judge and party on its own performance. Ask for an example of a campaign where they recommended a budget cut because incrementality testing showed it was over-attributed by the platform.
  • Profit literacy. Does the agency ask about product margin, customer lifetime value and tolerable CAC before proposing a campaign structure? A team that never asks these questions optimises for whatever metric is easiest to report, which is usually ROAS, which is usually disconnected from real profitability.
  • Account ownership. Is the Google Ads or Meta account registered in the client’s name with the agency in manager-level access, or registered in the agency’s name? The second arrangement transfers your historical data, audiences and learnings to the agency. When the contract ends, you start from zero. Account ownership belongs to the client, always.
  • Exit terms and data portability. What happens to custom audiences, conversion lists, campaign structures and historical performance data when the engagement ends? A serious agency documents the handover protocol in the contract, including timing, format and scope of what is returned. Silence on this point during the sales cycle is a red flag.
  • Seniority of the executor, not the salesperson. Who runs the account day to day, and have you met them? Many agencies put senior strategists in the room for the pitch and assign junior account managers to execute. When hiring a PPC agency, ask to meet the operational lead before signing, and verify their track record on accounts of comparable scale.

The Questions That Filter Real PPC Agencies from Pitch Decks

Most RFP question lists are too generic to differentiate finalists. The questions to ask a PPC agency that actually filter quality are operational and specific.

On measurement. “How do you measure the incremental impact of your campaigns versus what the platforms report? Have you ever run a geo holdout on a client account? Can you show me a report where you reduced a budget because the incremental ROAS did not justify it?” Agencies that answer with concrete examples beat agencies that answer with generic statements about transparency.

On business posture. “If a campaign shows a 4:1 ROAS on a product with a 10% margin, do you scale it? What questions do you ask about my margin before proposing a structure?” A finalist who scales without asking about margin is optimising for the metric, not for the outcome.

On team and exit. “Who will be my operational point of contact daily? Can I meet them before signing? What happens to my account, my audiences and my historical data if I terminate?” The right answer specifies a named senior, available for a pre-signature call, and documents the exit protocol. Vague answers or “we have never had a client leave” disqualify.

The pattern: agencies that answer in operational terms beat agencies that answer in commercial terms.

Red Flags That Should End the Conversation

Five patterns are the canonical PPC agency red flags. Any one of them should disqualify a finalist, no matter how strong the rest of the pitch is.

• Guaranteed results. Any agency that guarantees a ROAS, a lead volume or a CPA in pre-signature is either lying or covering an undisclosed risk. Auction dynamics shift, algorithms shift, competitive intensity shifts. No guarantee in this market is honourable.
• Refusal to run a free pre-engagement audit. A serious agency audits the existing account before proposing a contract, because the proposal needs to reflect the actual situation. An agency that skips this step is selling its standard product, not a response to your context.
• Master ownership of the ad account. If the agency asks to own the Google Ads or Meta account rather than to have manager-level access, the request is a retention mechanism dressed up as operational convenience. Decline it.
• Twelve-month minimum contract with no break clause. A healthy partnership accepts a 90-day pilot or a 30-day rolling notice. A locked twelve-month contract usually hides a model that depends on churn-resistant lock-in to be profitable.
• Reporting built on vanity metrics. Impressions, click-through rates and average position, presented without a clear mapping to conversions and revenue, indicate an agency that optimises for what looks good in a slide, not what shows up in the P&L.

One additional signal: agencies that refuse to share directly contactable client references, beyond logos on their website, are protecting themselves from scrutiny that should be welcome.

Why Measurement Independence Is the Single Best Predictor of Agency Quality

The deepest structural problem in the PPC agency market is that most agencies measure their own performance using the platforms they buy from. The ROAS reported by Google Ads is inflated by last-click bias and branded search inclusion. The conversions reported by Meta include cross-platform double-counting. An agency that reports these numbers without correction structurally overstates its own contribution. This is the problem that decides whether the retainer is producing real growth or paying for credit on demand that already existed.

The agencies that pass this filter do two things that the others do not. First, they integrate incrementality testing into their standard methodology, not as a premium add-on. Geo holdouts and conversion lift studies, with marketing mix modelling where budget permits, are operated quarterly, with results applied as correction coefficients on platform-reported ROAS. Second, they accept independent audit by an external consultant, the client’s analytics team, or a third-party measurement provider. An agency that refuses external audit is selling activity, not outcomes.

This criterion is verifiable in two RFP questions. Ask whether the agency has ever had a client account where an incrementality test showed one of its campaigns was over-attributed by the platform, and how it was handled. Then ask what the agency would do if the client commissioned an independent audit of its work mid-contract. The answers separate the agencies that build measurement independence into their operating model from the agencies that treat measurement as a marketing claim.

Match the Agency Profile to Your Growth Stage

A PPC agency that is right for an early-stage account is rarely right for an enterprise account. Match the profile to the stage.

• Early-stage or first paid programme. The priority is clean setup: conversion tracking that reconciles with the CRM, a focused search and Shopping structure to validate demand, and a learning velocity that turns a small budget into directional intelligence within sixty days. Incrementality testing is not relevant yet, not enough data. Hire an agency with strong process discipline, not one with a measurement science team.
• Scale-up. The priority shifts to multi-channel testing, segmented bidding strategies, and the first cycle of incrementality tests once total paid spend crosses approximately 500,000 euros per year. Hire an agency that can structure parallel experiments across Meta, Google and at least one upper-funnel channel, and that proposes a measurement plan beyond platform reports.
• Enterprise. The priority is measurement independence at scale, geo holdout cadence, integration with the client’s analytics or marketing science function, and reporting calibrated for financial control. Hire an agency with internal measurement science capability, quarterly holdouts, and comfort being audited by client teams.

The trap to avoid is hiring an enterprise-grade agency for an early-stage account, where there is nothing yet to measure, or hiring a boutique for an enterprise account, where the operational complexity exceeds the agency’s capacity.

Recap and Next Step

Choosing a PPC agency well comes down to a single structural shift. The standard criteria (sector expertise, certifications, team size, reporting cadence) screen for the baseline of professional competence. They do not predict outcomes. The criteria that predict outcomes are measurement independence, profit literacy, account ownership, exit terms and the seniority of the people actually operating the account. An RFP that filters on those criteria, with the operational questions above, and that disqualifies on the five red flags, will surface the agencies that deliver.

If you are running an RFP and want a second opinion on how your finalists actually measure incremental performance versus platform-reported ROAS, a 30-minute review with the Primelis paid media agency team can pressure-test the answers you have received before you sign.