By Timothy Jacqmin — Co-Founder, Nexuro Digital · August 2026
TL;DR
- A SEA agency (Search Engine Advertising) runs your advertising on search engines — mainly Google Ads, and today also Microsoft Ads and, since 24 August 2026, ChatGPT Ads.
- The job changed in 2026: with AI Max and Performance Max, an agency no longer tunes keywords one by one, it steers an AI — through the quality of its signals, product feeds, exclusions and measurement.
- In Belgium, budget €500 to €3,000 excl. VAT per month in media spend for an SME, plus management fees. Three billing models exist: percentage of media spend, monthly retainer, hourly rate — the first one creates a conflict of interest.
- The five criteria that separate a good agency from a bad one: account ownership, transparency on fees, conversion tracking installed and verified, reporting in euros (not clicks), and refusing to promise positions.
- At Nexuro: €80/h excl. VAT, a Google Ads account in your name, and a free audit of your existing account before any proposal.
A Belgian SME typing "SEA agency" into Google is rarely looking for a definition. It wants to know whether outsourcing its Google advertising is worth it, what it costs, and how to avoid handing €2,000 a month to someone who will burn through it in three weeks.
This article answers those three questions, with an angle most agency pages avoid: what genuinely changed in the profession in 2026, and why that shifts what you should demand from your provider.
SEA, SEM, paid search: what are we actually talking about?
SEA (Search Engine Advertising) means buying advertising space on search engines: your ads appear above or beside the organic results, and you mainly pay per click. It is the opposite of SEO, where position is earned through content and authority, without paying Google.
Three synonyms circulate, often misused:
| Term | What it actually means |
|---|---|
| SEA | Advertising on search engines (Google Ads, Microsoft Ads) |
| Paid search | The everyday English equivalent of SEA — strictly the same thing |
| SEM | SEO and SEA combined (Search Engine Marketing). The term is ambiguous and increasingly rare |
A "SEA agency", a "Google Ads agency" and a "paid search agency" are therefore, in practice, the same thing. If you want the acronyms laid out, we have collected them in our search marketing glossary.
What a SEA agency actually does
The work splits into six blocks. A serious agency should be able to show you what it does in each one.
1. Economic framing. Before any campaign: what a customer is worth, what acquisition cost is sustainable, how much search demand genuinely exists in your market. In French-speaking Belgium, many B2B niches amount to a few dozen searches a month — an honest agency will tell you that before selling you a retainer.
2. Account structure. Campaigns, ad groups, keyword match types, exclusion lists, extensions. This is the historically "hand-crafted" part of the job — and the one that changed most (see below).
3. Ads and landing pages. An ad is only as good as the page behind it converts. An agency that never has a word to say about your landing page is doing half the work.
4. Tracking. Without reliable conversion measurement, optimisation is blind and the algorithm learns the wrong lesson. It is today the most frequently botched part — see our guide on measuring your marketing's real ROI.
5. Day-to-day steering. Bids, budgets, search-term and placement exclusions, tests. At cruising speed: a weekly intervention, not a daily one.
6. Reporting. The only report that matters: how many euros invested, how many enquiries generated, at what cost, and what share turned into revenue. A report that stops at impressions and clicks is a report hiding something.
What changed in 2026: from tuning to steering
Google has shifted its search campaigns to AI-driven automation: AI Max left beta on 15 April 2026, and from September 2026 campaigns using automatically created assets and campaign-level broad match are automatically migrated to AI Max. The sunset of Dynamic Search Ads, initially planned for September, was pushed back by Google to February 2027 (official update of 11 June 2026).
What Google says about the results: around 7% more conversions or conversion value at a comparable CPA/ROAS when the full feature suite is enabled (search term matching, text customisation, final URL expansion) — Google internal data 2026, non-retail advertisers.
Add Performance Max, now a major channel, and the picture is clear: the advertiser no longer finely chooses where and when an ad shows; it supplies signals and guardrails to an AI that decides.
In practice, this moves an agency's value onto four points:
- Input quality. A clean product feed, explicit landing pages, complete creative assets, relevant audience signals. AI amplifies whatever you feed it — mistakes included.
- Guardrails. AI Max introduced brand controls, location controls and text guidelines. Using them is what stops you paying for off-topic queries or for your own brand name.
- Conversion signal quality. When the algorithm optimises on its own, the only thing it truly optimises is whatever you declared as a conversion. A "contact" form counted the same as a sale corrupts the entire learning process.
- Judgement. Knowing when to cut, when to let a campaign learn, when to decline one of Google's automated recommendations. That is where the difference between an agency and a dashboard is decided.
Put differently: the mechanical part of the job is disappearing, the strategic part is taking over. An agency whose sales pitch is still "we optimise your keywords every day" is describing a 2019 profession.
And one more channel has appeared: ChatGPT Ads has been running in Belgium since 24 August 2026. We covered how it works in ChatGPT Ads is coming to Belgium.
What does a SEA agency cost in Belgium?
Two lines have to be told apart: media spend (what you pay Google) and fees (what you pay the agency).
On media spend, a realistic floor for a Belgian SME sits around €500 to €1,000 excl. VAT per month in a local niche, and €1,500 to €3,000 in a contested market. Below that, the algorithm lacks the data to learn and the account stalls. Cost per click varies enormously by sector: we measured the Belgian ranges in how much Google Ads really costs a Belgian SME, and the method for setting a starting budget is detailed in Google Ads for SMBs: what budget to plan.
On fees, three models coexist:
| Model | How it works | The risk for you |
|---|---|---|
| % of media spend | 10 to 20% of what you spend with Google | A direct conflict of interest: the agency earns more when you spend more, not when you earn more |
| Monthly retainer | A fixed amount, often €300 to €1,500/month | Readable, but opaque: you do not know what is actually being done |
| Hourly rate | You pay for time spent, itemised | It demands discipline from the agency, but it is the only verifiable model |
At Nexuro, we bill €80/h excl. VAT, with the work itemised. This is not a commercial positioning choice: it is the only model in which our interest and yours point the same way — towards lowering your acquisition cost, not raising your budget.
How to choose a SEA agency: 5 criteria and 4 red flags
The five criteria that matter:
- The Google Ads account is in your name. You own it, the agency has access to it. Not the other way round.
- Tracking is verified in front of you. Ask for a test conversion, live. Plenty of Belgian accounts have been running with broken tracking for months without anyone noticing.
- Fees are separated from media spend on the invoice, line by line.
- Reporting is expressed in euros and enquiries, not only impressions, clicks and CTR.
- The agency knows how to say no. To a pointless campaign, to a budget too small to work, to an unsuitable channel. Sometimes the right answer is SEO rather than SEA — we wrote a whole article on that trade-off: SEO or Google Ads, which one to choose.
The four red flags:
- A guaranteed position ("first page guaranteed"): in SEA, position depends on the bid and the quality score, in real time. Nobody can guarantee it.
- Refusing to grant account access, or using an agency-owned "shared" account.
- Compensation purely as a percentage of spend, with no cap and no cost-per-acquisition target.
- The uncommented automated report: a Looker Studio export sent every month without analysis is not consulting.
SEA alone, or SEA plus SEO and GEO?
SEA buys immediate visibility; SEO builds it over time; GEO makes you citable by AI assistants. The three do not compete, they take turns.
The combination that works best for a Belgian SME: start with SEA to validate which messages and intents genuinely convert, reinvest that learning into SEO (the queries that convert in paid search are your best organic targets), then rebalance as organic climbs. Your Google Ads account data is, in that respect, the best keyword research tool you will ever own.
On the third pillar — visibility inside ChatGPT, Perplexity and Google's AI Overviews — we published a measured study: The state of GEO in Belgium 2026.
Where to start
If you already have a Google Ads account, the first step is not to change agency: it is to know what is inside the account. A serious audit answers five questions — does conversion tracking work, where does the budget actually go, which queries trigger your ads, what is your cost per enquiry, and how good is the landing page.
That is exactly what we do free of charge before any proposal. You leave with the diagnosis, whether you work with us afterwards or not. See our Google Ads (SEA) agency in Belgium page or get in touch.
FAQ
What does a SEA agency charge?
In Belgium, SEA agency fees take three forms: a percentage of media spend (generally 10 to 20%), a monthly retainer (often €300 to €1,500 excl. VAT), or an hourly rate. At Nexuro it is €80/h excl. VAT billed on time actually spent, with the initial audit free. On top of that always sits the media budget paid directly to Google, which remains your largest expense.
What does SEA stand for?
SEA stands for Search Engine Advertising. It refers to buying ads displayed within search results — overwhelmingly Google Ads, with Microsoft Ads (Bing) as a complement. The common French term for it is "référencement payant".
What is the difference between SEO and SEA?
SEO (organic search) earns positions in Google's unpaid results through technical quality, content and site authority: slow to build but durable and with no cost per click. SEA buys immediate visibility per click: traffic starts within hours but stops dead the moment the budget is switched off. The two complement each other rather than replace each other.
What is the minimum budget to launch Google Ads campaigns in Belgium?
Plan for at least €500 excl. VAT per month in media spend in a low-competition local niche, and rather €1,500 to €3,000 in a contested market. Below that floor, campaigns do not gather enough conversions for automated bidding to learn, and results stay erratic. It is better to concentrate a modest budget on a single well-targeted campaign than to spread it thin.
Do you still need an agency now that Google Ads is automated?
Yes, but the nature of the work has changed. Since the move to AI Max and Performance Max, an agency no longer sets keywords by hand: it defines the strategy, feeds the algorithm reliable signals (correctly measured conversions, product feeds, creative assets), sets brand and location guardrails, and arbitrates Google's automated recommendations. That is steering and judgement, not execution.
Who should own the Google Ads account?
You, always. The account should be created under your company identity and payment method, with the agency holding administrator access only. That is what guarantees you keep the account history — and therefore the learning accumulated by the algorithms — the day you change provider.
Can a SEA agency also run ChatGPT Ads?
Since 24 August 2026, ChatGPT ads have been served to Belgian users on ChatGPT's free tiers. Self-serve buying from Belgium was not yet open at the time this article was published, access going through OpenAI's teams and partners. How the format works and the exact state of its availability are detailed in our dedicated article.
Sources
- Google Ads — We're upgrading Dynamic Search Ads to AI Max, blog.google, 15 April 2026 (updated 11 June 2026): https://blog.google/products/ads-commerce/dsa-upgrade-to-ai-max-2026/
- Google Ads Help — AI Max for Search campaigns: https://support.google.com/google-ads/answer/15909989
- Google Ads Help — About Performance Max: https://support.google.com/google-ads/answer/10724817
- Nexuro Digital — Google Ads CPC benchmarks Belgium 2026 by sector (264 commercial keywords, July 2026)
