What does an SEO agency actually do?

An SEO agency's job is to make your website easier for Google to find, understand and trust, then keep improving it every month: technical fixes, an audit of what's holding you back, content that targets what customers actually search for, credible links from other sites, and reporting that shows what changed. The mix shifts depending on your site's starting point, but almost every legitimate retainer contains those five ingredients in some proportion.

What's actually in a typical SEO retainer?

Strip away the jargon and a month of proper SEO work breaks down into a handful of repeatable jobs. None of them are secret or proprietary — the skill is in doing them well and in the right order for your specific site.

Technical health checks. Site speed, mobile usability, broken links, crawl errors, duplicate pages, and whether Google can actually index the pages you want found. This is unglamorous plumbing work, but nothing else matters if Google can't crawl the site properly.

Keyword and content strategy. Working out what your customers actually type into Google — not what you'd guess — and mapping that against what's already on your site, what's missing, and what a competitor is ranking for that you aren't.

On-page optimisation. Title tags, meta descriptions, headings, internal linking and page structure, tuned so each page is unambiguous about what it's about and who it's for.

Content creation. New pages or articles built around the keyword gaps found above — the kind of guide you're reading now is a content-strategy output, not an afterthought.

Link building and authority. Earning mentions and links from other credible sites, because Google still treats being referenced elsewhere as a vote of trust. See what is local SEO for how this plays out for businesses with a physical trading area.

Reporting and analysis. Monthly (or more often) reporting on rankings, traffic and conversions, with an honest read on what moved the needle and what didn't.

Does the work change for a local business?

Yes — a plumber in Newport and a national e-commerce brand need different weighting of the same ingredients. Local businesses get more value from Google Business Profile hygiene, citation consistency, and location-specific content, and comparatively less from the heavyweight technical work a large site needs. If most of your customers are within driving distance, local SEO should dominate the retainer, not sit as an afterthought.

This is also where a lot of wasted spend happens. A national e-commerce agency's standard playbook — deep technical crawling, large-scale content production, competitive link campaigns — is often overkill for a single-location trades business, and the invoice reflects that overkill whether or not it moves the needle locally.

How much should this actually cost?

Scope drives price more than anything else. A single consultant working a focused local site typically sits at the lower end of the market; a full agency team covering technical, content and links across a large or national site sits much higher. For the full breakdown of UK pricing by model, see how much SEO costs in the UK — the short version is that a wildly cheap retainer usually means one or more of the five ingredients above is being skipped, not that you've found a bargain.

What should you actually get every month?

Deliverable	What "good" looks like
Reporting	Plain-English summary of rankings, traffic and enquiries — not just a screenshot of a dashboard
Technical work	A visible list of fixes made, not just "monitoring" every month with nothing changed
Content	New or improved pages tied to a specific keyword and a reason it was chosen
Links	Named, checkable sources — never a vague "50 links built" with no detail
Communication	Direct access to whoever is actually doing the work, not just an account manager

The honest counterpoint: what a good agency can't promise

No legitimate agency can guarantee a #1 ranking or a fixed timeline — Google's algorithm isn't controlled by anyone selling SEO, and results depend on your market's competition as much as the work itself. Anyone promising a guaranteed position by a specific date is either inexperienced or not being straight with you. What a good agency can promise is a clear list of what they did, why, and what changed as a result. It's also worth knowing that "agency" isn't the only structure that does this work: a freelance SEO consultant delivers the same five ingredients directly, without the account-manager layer.

Red flags that mean you're not getting the real work

Reports that only show vanity metrics (impressions, "visibility score") with no link to actual enquiries or sales. Monthly calls where nothing concrete changed since last time. Link-building described only in bulk numbers, never specifics. And retainers that never seem to move past "the audit phase" months in — a proper audit is a one-off deliverable, covered in what an SEO audit includes, not something billed indefinitely.

How to check you're getting what you're paying for

Ask for last month's report before you sign anything — a serious agency has one ready. Ask what specifically was published, fixed or linked, by name, not by category. And ask who does the hands-on work: the answer tells you more about value for money than the price on the invoice. If you're unsure how any of this applies to your own site, that's exactly what a free audit call is for.