Link-building services: consultant, agency or platform, and what the contract must include

You run marketing or SEO for a B2B company and are thinking of handing your links to a third party. Link-building services come from a consultant, an agency or a platform, and a netlinking service provider should be chosen on what it lets you control: the publishers, the anchors, the content and the proof of results, on Google as well as in the answers of generative engines.

This page helps you decide between a consultant, an agency and a platform, draft a contract that protects your budget, spot the offers to avoid and judge results at 3, 6 and 12 months.

What a link-building service should cover

A serious service handles all or part of the journey described in our guide to netlinking (diagnosis, publisher selection, campaign, proof). Before comparing offers, check which steps each one actually covers:

• Diagnosis: which URLs need links, and how many.
• Publisher selection: which domains, for which page, on which criteria.
• Purchase: negotiation and ordering, publisher by publisher.
• Copywriting: one article per publisher, built from a brief.
• Publication: going live, with a checked rel attribute and anchor.
• Monitoring: links still present over time, source pages still indexed.
• Reporting: links, positions and AI citations, page by page.

An offer that starts at the "purchase" step leaves you with the diagnosis and the proof, the two steps that decide profitability.

The diagnosis and the objectives agreement

A credible service starts with an assessment: where your links come from, which pages receive authority, which anchors dominate, where the risks lie. A link building audit provides this one-off inventory; the service must then turn it into written decisions, which you can call an objectives agreement:

• Priority pages: solution pages, categories, comparisons, pages that convert.
• Expected gain per page: consolidate a top 10, break into the top 3, defend a position.
• Link target per URL: the median number of dofollow referring domains among the top 10 results.
• Proof indicators: positions, clicks, conversions and citations in AI answers.

Without this document, the provider can only be judged on a number of links delivered, and you cannot attribute anything.

Checks before and after publication

What separates a service from a simple delivery is its checks. Every link goes through five verifications:

Mentions and AI citations: what the service must include

ChatGPT, Perplexity, Gemini and AI Overviews cite sources and name brands. Naming is not linking: the mention of your brand in the article carries the GEO signal, the link carries the SEO signal, and the two add up. An up-to-date service therefore also selects publishers that generative engines cite often, and measures the citations won or lost, not just positions.

Consultant, agency or platform: what you are really buying

The three models do not sell the same thing. The right question is not "which one is best?" but "what will I control, and what will I be able to measure?". The table compares the three on these criteria:

An agency brings continuity: processes, proofreading, activity that does not depend on a single person. In return, clarify who is responsible for strategy, copywriting, approval and reporting.

The hybrid model

Many teams combine models. A consultant or an agency sets priorities and approves choices; a platform provides the publisher catalogue, the order history and the reporting in one place.

SEO agency or link specialist

Links amplify what already exists. If the target page answers the intent poorly, stays thin or is badly indexed, part of the signal is lost. An SEO agency that also handles technical SEO, content and internal linking avoids this trap, provided the link side is as transparent as the rest.

The link-building consultant: missions, skills and limits

A consultant does not "place" links: they defend choices. Their missions cover four blocks:

• Audit the profile: anchors, topical consistency, pages that concentrate authority and under-supported strategic pages.
• Define acquisition: priority pages, link types, a pace with no unjustified spike.
• Qualify publishers: accept or reject each site, and document why.
• Report back: connect the links obtained to positions, conversions and citations.

Skills to check before signing

A consultant's competence shows in their ability to explain a method. In the interview, check three points:

• Reading metrics: they know what Trust Flow, Citation Flow and Topical Trust Flow measure, and what they do not tell you.
• Qualification grid: they cross metrics with relevance, traffic, identifiable authors, the contact page and the publisher's reach.
• Budget trade-offs: they can tell when strengthening a page's content pays more than adding links.

When a consultant is enough

A consultant is enough when you have few pages to strengthen, a content team able to produce, and the wish to keep control of every trade-off. They reach their limit when volume exceeds their prospecting and monitoring capacity: they then need the backing of a platform or an agency.

What the link-building contract must include

The median budget for an engagement that includes link building is €4,000 excl. VAT (La Fabrique du Net, 2026). At this level of commitment, every clause counts. Here are the ones that protect your budget, and why:

Add the cancellation terms before kick-off and the list of evidence supplied for each link: URL, date, anchor, attribute, indexation status.

What a provider can commit to

No provider controls the competition, Google updates or the quality of your pages: they cannot guarantee positions. They can, however, commit to what they do control:

• A process: initial diagnosis, selection criteria, approvals, schedule.
• Intermediate indicators: links published, source pages indexed, compliant anchors, stable links.
• Regular reporting: data, interpretation, proposed decisions.

If a results target still appears in the contract, formalise a protocol: pages concerned, baseline period, excluded events (redesign, migration), data source and the rule in case of a major Google update.

Copywriting and brief: who writes what

Depending on the offer, the article carrying the link is written by the provider, by you or by the publisher itself. In every case, it starts from a brief: keyword, intent, topics, questions, semantic field and publisher constraints (length, number of client links, free or imposed anchor). Its structure is detailed in our guide to the netlinking campaign.

Lost links and the guarantee period

A link can disappear, change attribute or lose the indexation of its page. Ask for the period during which presence is guaranteed and what the provider does if a link drops during that period. On the Incremys platform, links bought are covered by a 24-month guarantee, with an "active" or "expired" status in the reporting.

Red flags before you sign

Google classes undisclosed link buying among the link schemes targeted by its spam policies, and Penguin has run in real time within the core algorithm since 2016. Be wary of the following signals:

• Link bundles: a fixed volume, unrelated to your pages or to the gap to close.
• "PR9" links: public PageRank no longer exists; the label is a sales pitch.
• "Risk-free" links: an undisclosed paid link is still a link scheme.
• No list of publishers: you pay without knowing where your links will appear.
• A price unrelated to Trust Flow: compare the price per Trust Flow point.
• Guaranteed positions: nobody can commit to a ranking.

The full framework for a paid link (disclosure, publisher eligibility, value for money) is covered in our guide to buying backlinks.

Questions to ask in the meeting

A few questions are enough to tell a methodical provider from a volume reseller. Ask them before any commercial proposal:

• How do you choose the pages to strengthen, and how many links do you aim for on each?
• Which publishers have you rejected recently, and why?
• Who approves anchors and content before publication?
• What does your reporting contain, and does it compare each page with its state before the first link?

Measuring and attributing the effect of a link budget

The most common risk is not a penalty but a budget spent with no proof of effect. To attribute a result to links, you need to limit the other variables. The before/after method with constant content works in five steps:

• Choose stable pages: no redesign or major rewrite during the period.
• Date every link: publication date, target page, anchor, indexation status.
• Set the windows: 28 days before the first link, then 28 to 56 days after.
• Log external events: seasonality, promotions, template changes.
• Read the same indicators: positions, clicks, conversions and AI citations per question.

The aim is to know which pages deserve more links, which need content work first and which plateau despite links.

Correlation, never causation

Honest reporting compares each page with itself, before its first link and today. It shows a coincidence in time between published links and a gain in positions or citations; it never states that a link produced a citation. Be wary of a provider who claims otherwise.

Judging results at 3, 6 and 12 months

The effects of a link arrive gradually, and the question to ask changes over time. The table shows what to look at and what to decide at each horizon:

At 3 months, you judge the quality of execution; at 12 months, the effect on visibility.

Depending on your situation

The choice of provider depends on the stage you are at. Here is where to go next:

• You do not yet know which pages to strengthen: start with the backlinks strategy and its URL-by-URL diagnosis.
• You want to inventory your current links: the method is described in our guide to backlink analysis.
• You want to read how your links evolve over time: gains, losses and correlation are covered in backlink history.
• You prefer to manage your purchases yourself: the criteria to check are gathered on our page about the netlinking platform.

If you are looking for end-to-end support, Incremys' SEO, GEO and link-building support handles, at the time of writing, the strategy, publisher selection, copywriting and monitoring in the platform. Articles are written by the Content Factory or by the publisher depending on the offer, and the reporting tracks link presence, positions and ChatGPT citations won or lost.

FAQ: netlinking service provider

What is a link-building service?

A link-building service is a service that earns links and mentions from other sites to improve your Google rankings and your presence in AI answers. It covers diagnosis, publisher selection, purchase, copywriting, publication, monitoring and reporting. Check which steps are actually included before comparing offers.

Agency, consultant or link-building platform?

The right model depends on what you want to control and on your internal time. A consultant suits close control of a moderate volume, an agency suits delegating a complete set-up, and a platform suits choosing every publisher yourself. Many teams combine strategic support with a platform that centralises orders and reporting.

What should a link-building contract include?

A link-building contract must name the publishers before purchase and require the sponsored attribute for paid links. It also specifies who approves anchors, who writes and who owns the content, the link guarantee period and what the reporting contains. A budget set per URL protects you better than a link bundle.

How do you judge a link-building agency?

A link-building agency is judged on its method, its transparency and its willingness to reject publishers. Ask how it chooses the pages to strengthen, which sites it has turned down and why, and what its reporting contains. Link bundles, "risk-free" promises and no list of publishers are red flags.

What results should you expect after 6 months?

After 6 months, a service should show links that are live, compliant and on indexed pages, as well as a smaller gap between your dofollow referring domains and the target set per URL. The full effect on positions and citations is better judged at 12 months.

Are the links guaranteed?

A link is only guaranteed if the contract sets a presence period and specifies what happens if it disappears. Check this period before signing and ask for a status per link in the reporting. On the Incremys platform, links bought are covered by a 24-month guarantee; links imported from another provider are not covered.

Who writes the articles?

Depending on the offer, the article carrying the link is written by the provider, by you or by the publisher. The contract must state this, along with ownership of the content. In every case, the article starts from a brief that sets the keyword, intent, topics, semantic field and publisher constraints.

Can a provider guarantee positions?

No serious provider can guarantee positions, because rankings also depend on the competition, your pages and Google updates. They can commit to a process, to intermediate indicators such as links published, indexed and stable, and to regular reporting that connects links to positions and citations.