What an SEO agency costs

1. What you actually buy from an SEO agency

The word “SEO” covers four distinct trades, which a quote often presents as one. Knowing which one you are being billed for changes the reading of the price entirely.

• Technical audit. Checking that the site is crawlable and comprehensible: response codes, robots.txt, sitemap.xml, title tags and descriptions, structured data, behaviour of missing pages, weight and speed. It is bounded work, done in a few days and redone periodically.
• Keyword strategy. Choosing which queries to target — the ones that bring buyers rather than browsers — and spreading them across pages. It is the most decisive work and the least visible on an invoice.
• Content production. Writing the pages that target those queries. It is the heaviest item, the one that never stops, and the one whose volume is always underestimated.
• Authority. Getting other sites to cite you. It is relational work, slow, and the only kind no tool spares you.

An agency billing a single monthly retainer blends those four lines. Asking how it breaks down is not a sign of distrust: it is the only way to know whether you are paying for regular production or passive monitoring.

2. Billing models, and what they cover

Amounts vary far too much by country, sector and site size for a figure quoted here to mean anything. The structure of the price, however, is stable, and that is what you need to be able to read.

• The one-off audit. A report delivered once. Useful for knowing where you stand, with no effect of its own: an audit fixes nothing, it lists. The real cost comes afterwards, when the recommendations have to be applied.
• The monthly retainer. The dominant model. It buys a volume of recurring work, often expressed in days or in a number of content pieces. Points to check before signing: the commitment period, what happens on termination, and who owns the content produced.
• Time and materials. Billed by the day. Transparent about the nature of the work, but it transfers the steering to you: you decide what gets done, so you have to know what needs doing.
• Payment on results. Appealing, and worth examining closely: the result billed is often the position of a keyword, which can be reached on a query nobody types. A ranking is not a customer.

In every case, one rule holds: search visibility takes months before it produces, and a short contract mechanically has no time to demonstrate anything. This is not a sales argument, it is a property of the channel — and it is also what makes commitment hard for a business with no budget.

3. Why it is a subscription, not a project

A website gets delivered. Search visibility does not — and the reason lies in three permanent movements.

• Your competitors publish. A ranking is not acquired, it is contested. The page that was first last year has not changed; what surrounds it has.
• Engines evolve. Criteria shift, the display of results changes, new surfaces appear — AI-generated answers being the latest example. Work that was compliant two years ago may no longer be.
• Your site moves. A redesign, a deleted page, a broken link, a change of address: each of these can wipe out months of progress without anyone noticing before the following quarter.

Which is why the real question is not “what does an SEO agency cost” but “who watches my site in the month I am not thinking about it”. A service that stops leaves a site frozen in a state that degrades on its own.

4. The warning signs of a service that will not hold

A few signs can be spotted before signing, and none of them requires technical skill.

• A guaranteed first place. Nobody controls a search engine's ranking. A position guarantee is either an unverifiable promise or the quiet targeting of queries nobody competes for — and therefore nobody searches.
• A report with no evidence. A ranking table with no capture of the results, no measurement date and no indication of the country or language queried cannot be verified. The same keyword does not hold the same position seen from Paris and from Montreal.
• No visible output. If the past month produced no page, no technical fix and no citation obtained, it produced nothing at all, however thick the report.
• Content ownership left vague. The pages written for you must remain yours after the contract ends. That is a clause, not an obvious given.
• Buying links in volume. A risky practice, whose penalty falls on your domain and not on the supplier.

5. Doing it yourself: what it costs in time

The first alternative to an agency is to handle it yourself, and it is perfectly viable — provided you count time as an expense, which is systematically forgotten because it appears on no invoice.

The work breaks down like this: check the technical state of the site periodically; record rankings on the targeted keywords, country by country; regularly write pages that answer a real question; watch what competitors publish; fix what breaks. None of these tasks is difficult. All of them demand consistency — and consistency is exactly what a busy owner cannot guarantee, as the page on the cost of a role describes.

The typical outcome is well known: an energetic start, a ranking record kept for six weeks, then nothing. Doing your own SEO rarely fails through incompetence; it fails through interruption.

6. Search visibility kept by a team of agents

This is the third way, and it is what nullbot offers. Not “a free audit”, but a team that keeps the work going over time — the part the agency bills monthly and the part an owner working alone ends up abandoning.

What is genuinely in place, and verifiable in the product:

• The site audit, measured rather than asserted. The engine fetches the page, the robots.txt, the sitemap.xml, the llms.txt, and even probes how missing pages behave. It returns an overall score and a score per category — technical, content, AI readability, structured data, performance, mobile and sharing — with, for each failed check, the matching recommendation ranked by impact.
• Ranking tracking, with its evidence. Every keyword carries its country and language of verification. Every measurement leaves a dated line in a history, with the position, the address found and the top of the results at the time of the record. The current position, the previous one and the best ever reached are kept — which is what lets you tell progress from fluctuation.
• Competitors tracked. A list of monitored domains, so you measure share of voice instead of staring at your own figures in a vacuum.
• An action plan you can delegate. Findings become actions ranked by impact, which an agent takes on — rather than a list of recommendations waiting for someone to find the time.

The difference in kind from a tracking tool is there: a tool displays rankings. Here the fix is made, and you see what was done.

7. The new question: being cited by AI, not just ranked

A growing share of searches no longer ends in a list of links but in an answer written by an assistant. In that setting, the question is no longer “what position am I in” but “am I cited, and with which source”. It is work distinct from conventional SEO, and most services do not mention it yet.

It is steered the same way, with facts: a list of questions your customers would genuinely ask an AI, the assistant queried for each one, and the finding recorded — absent, mentioned, or cited as a source — with the excerpt observed, the addresses cited as sources, and the competitors named in the answer. Every check leaves a dated trace, exactly like a ranking record.

On the site side, readability by models is checked: presence of an llms.txt at the root, no blocking of AI crawlers in the robots.txt, identity declared in structured data, a usable summary, and content of substance rather than a brochure. How it works is described separately.

8. What no agency and no agent can promise

Three limits, stated plainly — including for us.

• No ranking is guaranteed. Position depends on an algorithm nobody outside controls, and on competitors who are working too. What can be guaranteed is the work carried out and its trace, never its result.
• No quantified saving is promised. Comparing a subscription with an agency quote only makes sense for a given scope and a given volume. What differs with certainty is the nature of the expense: a service commitment on one side, a cancellable subscription on which each task has a consultable cost on the other.
• Authority remains human work. Getting a serious site to cite you takes a relationship, a real publication, sometimes a commercial move. An agent can prepare, identify and draft the request — it does not replace the relationship itself.

These limits are not cautious reservations: they are the points at which a promise that sounds too good should make you walk away, whoever the supplier is.

9. Frequently asked questions

Going further

Read next: how SEO and GEO visibility work on nullbot, running a business with no marketing budget, or governance and budget control.