Paid search agency: what to expect from it, what stays with you

Paid search buys a place in the search results: it is fast, it can be steered, and it stops the day you stop paying. Handing that lever to a paid search agency therefore means settling three questions: what you delegate to it, what you keep, and what you will judge its work on in three months.

This page is written for the marketing director or executive assessing a paid search provider: the scope of the engagement, the responsibilities that stay with the advertiser, the measurement without which no optimization is credible, a framework for reading a report. It also sets out what paid search teaches organic, and therefore how it fits with the work of an SEO agency.

What paid search covers in an agency, and where its scope stops

In an agency, paid search aims to capture existing demand at the moment it is expressed, on a pay-per-click auction model (PPC). That gives speed and control (budget, schedule, targeting), but visibility stops when the investment stops: that is the structural limit of paid search.

A serious engagement does not come down to “adding keywords”. It covers:

• strategy;
• account structure;
• continuous optimization;
• reporting geared to business objectives (awareness, leads, sales);
• post-click alignment (landing pages, messaging, evidence, journey), to avoid buying traffic that does not convert.

Paying to send a user to a slow or confusing page amounts to buying bounces.

The typical scope of a paid search engagement

A paid search agency works on the search ad platforms, and its scope breaks down into five blocks:

• Strategy: objectives, segmentation (brand / non-brand, intent, areas), budget envelope and schedule.
• Execution: campaign architecture, ads, extensions, audiences, exclusions, landing pages.
• Measurement: conversion definitions, data imports (including offline), tracking quality, Analytics consistency.
• Optimization: bids, search terms, negative keywords, creative tests, traffic quality, trade-offs.
• Reporting: ROAS, CPA, CTR, conversion rate, but also contribution to pipeline and revenue where possible.

Not every element of an engagement can be committed to in the same way:

A serious agency accepts to hold to the first three. The line between what a provider can guarantee and what it cannot is detailed in our guide to choosing an SEO agency, linked above.

What stays with you

On the client side, two points are non-negotiable: (1) you remain the owner of the ad accounts and of the data; (2) you sign off on the objectives (target CPA, conversion volume, areas, legal constraints and messaging, for example). These two points break down into a short list, the mirror image of the agency's scope:

• The ad accounts: opened under your entity, accessible to the agency, never held by it.
• The data: spend, search term and conversion history, the audiences built, exports, retrievable at any time and at the end of the contract.
• The objectives: target CPA, expected conversion volume, areas, seasonality, commercial priorities.
• Legal constraints and messaging: mandatory notices, permitted claims, brand promise.
• Sign-off on the landing pages: what they promise binds you, even when the agency writes the ad that leads to them.

This split is not a sign of distrust: an agency works better when the framework is set. A good provider turns data into recommendations and into execution, while leaving decision-making and governance to the teams, internal or agency-side, provided the contract says which one decides what. That framing happens at the RFP stage, and four pieces belong to choosing a search engine marketing agency, which equips that buying decision end to end:

• the requirements document;
• the scoring grid;
• the commitments;
• the governance.

What to require before any optimization

Without reliable measurement, optimizing means steering blind. It is the first point to check, and it is a blocker. Until it holds:

• no CPA commitment means anything;
• no report can be read;
• no automation is defensible.

An agency has to secure:

• Conversion definitions: micro (phone click, download) versus macro (qualified lead, opportunity, sale).
• Deduplication: stopping the same action from being counted several times.
• Consent: consistency of tracking with your constraints (banners, tags, Analytics).
• Offline imports: in B2B, tying the click to a CRM opportunity changes how ROAS reads.

This step conditions the quality of automated bidding strategies and the credibility of the reporting. Before accepting that part of the decisions be automated, three prerequisites are checked on your side:

• Reliability of conversions: a noisy conversion teaches automation badly.
• Volume: too little data makes the algorithms unstable.
• Room for manoeuvre: when CPC rises on saturated queries and a trade-off is needed.

None of the three can be established after the fact.

Acceptance criteria for an action, and traceability of changes

The value of an agency is not “more buttons”: it is a system of governance and quality control. Managing as a team makes it possible to industrialize:

• a prioritized roadmap (quick wins versus structural work);
• decisions justified by data (and not by opinions);
• clear acceptance criteria (how to check that an action genuinely improves CPA/ROAS);
• rituals (weekly for hygiene, monthly for strategy) and traceability of changes.

This framework limits a common risk: “optimizing” with no measurement loop, then finding out too late that volume rose but profitability did not. Ask that every action taken comes with the indicator meant to move and the deadline at which it will be judged. That is what separates a recommendation from a hunch, and it is what makes assessment possible three months later.

Traceability itself fits into a dated change log:

• what was modified;
• by whom;
• for what expected effect.

Without that log, a swing in performance stays uninterpretable, and both parties end up defending unverifiable assumptions at review time.

Paid and organic: what each one buys

Paid search and SEO do not buy the same thing:

The distinction is not only a matter of timing, because attention is not shared equally between the two surfaces: 70–80% of users say they ignore paid ads (HubSpot, 2025). When you pay, you therefore have to know precisely why and for what impact; the up-to-date SEO statistics give the orders of magnitude to base that trade-off on.

Paid search can make up for the absence of positions in the short term, but it does not replace the organic asset. Even when the contractual scope stays advertising-only, a mature agency has at minimum to coordinate the landing pages (content, evidence, experience, speed) and the segmentation by intent, between decision queries and consideration queries. In B2B, the best approach is often unified management of the two.

The most common trap on the acquisition side is running paid search without capitalizing on what it teaches. Yet it is the fastest learning loop you have; within a few weeks it says:

• which queries trigger conversions, and not only clicks;
• which arguments earn clicks;
• which objections block on the landing pages (bounce rate, form abandonment).

Content that answers those objections (guides, comparisons, FAQs) pre-qualifies the audience and reduces the pressure on the media budget. Structured, verifiable and neutral, it also stands a better chance of being picked up in generative answers. The benefit reads on both sides: fewer objections to handle after the click, and a body of content that keeps answering when the media budget has stopped.

Visibility, moreover, no longer comes down to the click: more than 50% of Google searches display an AI Overview (Squid Impact, 2025), and the citation of a source in a generated answer cannot be bought; our up-to-date GEO statistics track how that measure evolves.

Each channel then keeps its role, provided the intents are segmented:

The immediate decision is therefore not reserved for paid search: the two often compete for the same query.

Assessing a paid search agency

Three months after the start, the question is not “is it running?” but “does it hold?”. Useful reporting does not stop at adding up clicks. It connects:

• spend;
• traffic quality;
• conversions;
• business value.

The benchmarks that follow serve a decision:

• continue;
• renegotiate the scope;
• stop.

The six indicators, and how to read stability

The indicators depend on your model, but a B2B assessment baseline includes:

Also assess stability and the ability to explain variations with testable hypotheses. Stability reads on three signals:

• CPA drifting;
• CPC climbing;
• creative fatigue.

An agency that cannot say why one month was better than the previous one will be no better at reproducing the result the month after. Strong volume alongside a drifting CPA is a signal to deal with before it becomes a trend.

Reading a report with no sector benchmark

There is no universal figure for “thresholds”: the only reliable reading compares:

• your performance over time;
• by segment (intent, area, device);
• with change annotations.

In B2B, the “form” conversion is not enough; as far as possible:

• spend has to be tied to pipeline and revenue;
• a clear brand / non-brand segmentation has to be kept;
• offline statuses (qualified lead, opportunity) have to be imported where the organization allows it.

That level of reading avoids “cosmetic” optimizations: good CTR, poor pipeline. So require these indicators to be presented as a series, never as an isolated month.

The same reading applies to ad formats. Choosing them is the agency's job, but justifying them is yours: the right format is the one whose contribution to the journey you can explain, not the one that “delivers volume”. A format nobody on your side can account for is a budget line with no hypothesis, and a line with no hypothesis cannot be defended in a steering committee.

The three rituals that make management verifiable

Effective management rests on simple rituals:

• Weekly: hygiene (search terms, exclusions, budgets, anomalies, traffic quality).
• Monthly: review by intent, budget trade-offs, test backlog (ads, landing pages, audiences).
• Quarterly: alignment with business objectives, changes to the offer, decisions on what you buy and what you build.

This way of working limits inaction (recommendations produced then never applied) and creates a continuous improvement loop. The weekly meeting is the one that holds the trajectory, in four steps:

• analyse;
• decide;
• deploy;
• check the impact.

Ask for these meetings to appear in the contract, with their agenda and their attendees.

A cadence with no written record is worth nothing: what is not recorded does not resurface at the review, and it is always at the review that the gap appears between what had been decided and what was actually deployed. It is also at that pace that you can tell the agency applying its own roadmap from the one rewriting it every month to avoid having to account for the previous one.

Depending on your situation, two further reads extend this one. Your organic results are starting to hold on part of your queries: if you are looking for which ones you can stop buying and when, the trade-off is made query by query, and that is the work of an SEO and SEA consultant, who also handles the gradual shift from paid to organic.

Your trade-off goes beyond the paid / organic pair: if several acquisition levers are in play, the overall framing settles it, and a webmarketing agency covers that multi-lever management through data.

To track, query by query, the share of demand organic already covers and the share you still have to buy, the Incremys SaaS 360 platform centralizes the management and measurement of your organic and AI visibility.

FAQ: paid search agency, scope, measurement and pricing models

What does an agency do beyond launching the campaigns?

It runs continuous optimization: analysis of the actual search terms, exclusions, ad tests, targeting adjustments, landing page improvements, and reporting geared to ROAS and CPA. It also documents the changes, so that it can explain performance variations instead of merely noting them.

How does working with a specialist paid search agency work?

You set the objectives: volume, target CPA, areas, constraints. The agency structures the campaigns, sets up or checks the tracking, launches the tests, then optimizes on the data. You remain the owner of the account and keep access to the statistics, during the engagement and after it, and you sign off on what the landing pages promise.

How does an audit before taking over an account work?

The audit the agency delivers covers account structure, search term quality, targeting (areas, devices, schedules), exclusions, ads, and above all conversion measurement: deduplication, consistency with your Analytics tools, offline import where applicable. Until that measurement is reliable, no optimization is credible. It has to end in a prioritized roadmap, with acceptance criteria attached.

How do you measure the ROAS of a campaign managed by an agency?

ROAS is calculated as the revenue attributed to the campaign divided by the ad spend. For it to be reliable, conversions and values have to be measured correctly (in e-commerce, or through a B2B proxy via offline imports and the pipeline where possible) and brand and non-brand have to be clearly segmented. In the reporting, read it as a series, never as an isolated month.

What does management cost: flat fee, percentage or hybrid model?

Common models combine a flat fee for ongoing management, a percentage of spend when budgets are large, or a hybrid of the two; the monthly flat fee dominates market practice.

As benchmarks, the median budget of a Google Ads engagement (fees) stands at €10,000 excl. VAT and that of a paid search engagement, fees excluding media budget, at €15,000 excl. VAT (La Fabrique du Net, 2026). In every case, keep the media budget separate from management fees and have a clear scope written into the quote: optimizations, rituals, reporting, support on the landing pages.

Can one agency handle SEO and paid search together?

Yes, and it often makes sense: paid search acts as a fast learning loop (which queries convert, which promises earn clicks) and organic turns those learnings into lasting assets: pages, content, FAQs. The condition is a clean segmentation of intents, so that each channel knows what it is capturing and the media budget does not buy back what organic already covers.