The essentials
- Five skills: a measurement plan and tagging, multi-source consolidation, analysis and recommendation, GDPR compliance, transfer of skills.
- 2026 pricing: €600 to €1,200 a day at an agency, €450 to €900 with a senior freelancer; monthly support for a small business runs between €500 and €2,500.
- Clauses to demand: ownership of the accounts and the dashboards, administrator access for the client, reversibility, dated deliverables.
- Warning sign: an agency that talks about tools before it talks about your objectives and your data.
"Data marketing" covers very different services in 2026: placing tags, building dashboards, performance analysis, data science, sometimes simply reselling licences. Choosing an agency means knowing what you expect, then checking specific skills rather than references. This grid focuses on the needs of a small or mid-sized company: measure correctly, consolidate, decide.
Clarify the need before consulting anyone
Three distinct needs call for three agency profiles. The first is measurement: configuring GA4, Google Tag Manager, advertising conversions and consent, which is a technical skill; the services and deliverables are described in the deliverables of a GA4 provider. The second is steering: building and maintaining a multi-source dashboard the leadership team can read. The third is analysis: reading the data every month, explaining the gaps, recommending actions. Few agencies excel at all three; a small business mainly needs the last two, the first being a one-off engagement.
The five skills to check
| Skill | How to check it | Expected answer |
|---|---|---|
| Measurement plan | Ask for an anonymised example tagging plan | A document listing events, parameters and triggers, with the business objectives alongside |
| Consolidation | Ask which sources are connected in an existing dashboard, and how | Named connectors, the refresh frequency, how history is handled |
| Analysis | Read a real monthly report produced for a client | Gaps explained and dated recommendations, not annotated charts |
| Compliance | Ask how consent is handled and its impact on the figures | A consent platform named, an estimated refusal rate, a correction method |
| Transfer | Ask what the client can do alone after six months | Training planned, documentation handed over, administrator access for the client |
The questions that separate the candidates
- "Which three metrics would you put at the top of our dashboard?" A good agency first asks about your objectives and your business model; a poor one answers "sessions, bounce rate, followers".
- "Who owns the accounts and the dashboards at the end of the contract?" The only acceptable answer: the client, with administrator access from day one.
- "How do you measure your own added value?" Expect a quantified answer: cost per enquiry before and after, decisions taken thanks to the analysis, hours saved.
- "What happens when an API changes and breaks the dashboard?" The response time, and whether it is included in the fee.
- "Can you show us a case where you recommended reducing a budget?" An agency that has never advised spending less is optimising its fees, not your results.
Prices and billing models in 2026
| Service | Agency | A senior freelancer | Note |
|---|---|---|---|
| Day rate | €600 to €1,200 | €450 to €900 | Low rates often hide junior profiles |
| Audit and measurement plan | €2,500 to €8,000 | €1,500 to €4,000 | A one-off engagement of 3 to 10 days |
| A multi-source dashboard | €3,000 to €12,000 | €800 to €3,000 | Excluding connectors and licences |
| Monthly support for a small business | €800 to €2,500 | €500 to €1,500 | Reading, analysis, recommendations, maintenance |
| Licences and connectors re-invoiced | A markup of 10 to 30% | Often at cost | Ask for the original invoice |
The detail of analytics support costs is covered in what analytics support costs. For a small business, a common alternative is to buy a marketing platform at €39 to €250 a month and two to four days of consulting a quarter rather than a monthly retainer.
The contract clauses
- Ownership: the GA4, Google Tag Manager and Ads accounts, the dashboards and the documentation belong to the client; the agency is a user, never an owner.
- Dated deliverables: the measurement plan within 30 days, the dashboard within 60 days, the first analysis report within 90 days.
- Reversibility: handover of the documentation and a two-hour handover session at the end of the contract, at no charge.
- Term: an initial commitment of 3 to 6 months, then monthly with one month's notice. Twelve-month commitments are only justified with a significant initial investment.
- Subcontracting: declaration of the freelancers or third-party platforms accessing your data.
The warning signs
Be wary of an agency that promises results before seeing your data, refuses to give administrator access, offers its own tool with no export, whose example report contains more charts than sentences, or asks no questions about your margin and your objectives. The method for judging the value delivered after signing is detailed in judging whether your supplier brings value.
How GreenRed helps
Rather than juggling several tools, GreenRed's Overview module brings these metrics together in a single dashboard, compares them over time and tells you which actions come first. You can try it free, with no card, from the Pricing.
Frequently asked questions
An agency or a freelancer for a small business's data marketing?
A senior freelancer suits a stable scope of two to six sources, at 30 to 40% less. An agency brings continuity (cover during absences) and multiple skills for multi-brand or international projects. In both cases, insist on meeting the person who will do the work.
Do you need a Google-certified agency?
The Google Partner certification concerns Google Ads and measures managed spend, not data competence. The individual GA4 certifications are free and quick to obtain. An example measurement plan and a real report tell you far more than badges.
How long before you see a data marketing agency's value?
The first deliverables (measurement plan, dashboard) arrive within 60 days. The analytical value, meaning decisions taken thanks to the data, is judged after 3 to 6 months, the time it takes to have reliable history and two or three cycles of recommendations.
What if the current agency refuses to hand back the access?
The accounts created for your company belong to you. Ask in writing for the transfer of ownership of the GA4, Tag Manager and Ads accounts, then contact Google support with your documents if the agency doesn't respond. For the future, have every account created with an address on your own domain.