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What does an SEO agency do?

It’s a fair question. Many people have heard of SEO - search engine optimisation - but not everyone will know what it means.


First we'll define the term:

SEO is a branch of marketing whose goal is to increase visibility in organic search engine results.


Nothing too complicated.


Earlier in its history, success was marked by improving rankings for key search terms, but with changes in how search engines work, things are a bit more nuanced. The goal is to increase visibility in searches across devices and audiences, and to enrich user journeys through websites to increase the likelihood of them converting (moving from prospects to customers).


The term organic means non-paid, meaning a focus on techniques with enduring value, rather than ones which dry up as soon as your advertising budget is switched off.


An SEO agency is simply an external company who does those things for your business.

Working with an SEO agency can help your business to achieve these things:

  • Better visibility
  • Better traffic
  • More leads
  • More conversions
  • Better ROI

But what exactly do they do to make those things happen?

In short, these things:

  • Communicate with you

  • Audit your site

  • Outline objectives

  • Carry out keyword research

  • Analyse any penalties affecting your site

  • Analyse your current link profile

  • Optimise existing content

  • Optimise site structure

  • Do other technical SEO

  • Create new content

  • Build links

  • Outreach

  • Monitor brand mentions

  • Monitor results

  • Report on results


It’s a beefy list. More information on each activity is given below:

Communicate with you

At the on-boarding stage an SEO agency should look to understand everything about your business. Your goals, your assets, your existing campaigns; any previous SEO work you've had done, either internally or externally; the specific challenges you are facing, and the gaps in your knowledge.

This information shapes the campaign they will create and implement for your business. Ongoing communication is based around reporting on results, and refinement of goals and strategy to maximise its relevance.

🚩 If an SEO agency makes no effort to keep you in the loop, that's a bad sign.

Audit your site

Assessing the current performance of your site, and looking for opportunities to improve, is a vital part of the onboarding process. A detailed audit lays the foundations for a meaningful ongoing SEO campaign.

To do this effectively, an SEO agency will need access to your site, your Google Analytics account (or other analytics software), and your Google Webmaster tools account (if relevant). If you are not set up on these Google services (or equivalents), they may require you to do so for effective monitoring of ongoing efforts.


Young design team having a meeting together in creative office

Outline objectives

With the information and insights gained in the above steps, an agency will create an SEO campaign with objectives to achieve your goals. This will outline planned activities in any number of the areas below, depending on the scope and specific objectives.

Having a hard copy of the campaign strategy allows you to refer back to it as the campaign progresses, making sure planned activities are being completed and objectives are being met.

🚩 If an SEO agency will not share their planned campaign strategy and objectives, tell them you need to see this before work (and payment) can commence.

Carry out keyword research

Keywords are an integral part of SEO, and good keyword research can make or break a strategy. Understanding how real people search for goods and services allows you to optimise your communications and increase your chances of appearing in the right searches.

With machine learning, search engines have an evermore powerful grasp of user intent, related keywords, and semantics. This means you need to be aware of all the ways prospective customers search for products and services related to your business.

🚩 If an SEO agency doesn't ask about keywords during onboarding, ensure they are using relevant topics and terms that align to your prospects buying intent.

Analyse any penalties affecting your site

Search engines update their algorithms frequently, and some updates are implemented with the intent of penalising sites that have violated guidelines, or to devalue SEO techniques that are now considered out of date.

It's a bit of a cat-and-mouse game: SEO practitioners find something that delivers success, such as guest posting did earlier in this decade. Then the tactic gets popular, people figure out ways to exploit it, and things start to get spammy. Search engines then update their algorithms to devalue the spammier implementations of tactics, and the cycle repeats.

Understanding whether your site has been hit by any penalties is vital. This could be punishment for deliberately shady work from a previous agency, or from something that was OK once but is now discouraged. Studying your traffic and seeing whether there are any big drops after past search engine updates allows an SEO agency to identify penalties impacting your site, and take the necessary steps to correct things.

🚩If an SEO agency is not aware of the need to look for penalties, this may indicate other gaps in their knowledge.

Analyse your current link profile

One outcome of this step is the identification of low-quality backlinks that could be dragging your site down. Websites organically accrue links, not all of which will be good; but previous SEO agencies may have knowingly built links that were bad at the time. Additionally, links that were previously considered good may have fallen afoul of interim updates.

Identifying harmful links lets an SEO agency disavow them: effectively telling Google "we're aware of these bad links, we've tried to get them removed but we can't, so can you please ignore them".

Another outcome of link profile analysis is identifying gaps where links should be coming from. If you're the only site in your niche that isn't mentioned on a big industry news site, for example, this presents a great opportunity.

🚩If an SEO agency is not focusing on quality, they may engage (perhaps accidentally) in harmful link-building practices. If in doubt, ask them how they differentiate between ‘good’ and ‘bad’ links.

Optimise existing content

This includes rejigging page copy, blog content, and other site copy to make it SEO-friendly. In times gone by this meant stuffing more keywords in; but now it means making the content more user focused, natural, and query driven.

Optimisation also includes removal of duplicate content, thin content (including bulk copy that doesn't add any value), and broken pages.

SEO-specific content like meta titles and descriptions will be optimised or, if absent, created. This is one of the first things search engines see that gives them context about your site, and it is the preview that human users see in search engine results. So getting this right is very important.

🚩If an SEO agency is using out-of-date keyword optimisation practices, it can have a detrimental effect - avoid the likes of ‘keyword stuffing’ and ask them what they look for in a well optimised page.

Optimise site structure

Navigation through a website should be natural and intuitive, with content as few clicks away from the homepage as possible. It is often the case that websites built over time by non-specialists can become a bit of a mess, so an SEO agency will audit the structure of your site and make recommendations to improve it.

Optimisation of navigation also helps search engine crawlers to get a better idea of the structure and layout of your site. Often they will only browse a few layers deep into your navigational structure, so if key content is buried at the end of a long series of links, it may never be seen by search engines.

Each URL on your site should point to live content, redirect to another piece of content, or lead to a 404 page. Users should not encounter any dead pages.

🚩 If an SEO agency make no mention of having looked at your site structure, ask them why.

Do other technical SEO: under-the-bonnet tweaks

Technical SEO tweaks fine tune the way your site works, ensuring it is fast and legible across all devices. An SEO agency will look at things like this, all of which are ranking factors now (i.e. your site will rank better if they are done):

  • Site speed: along with steps to reduce page load time across all devices

  • Making content responsive: so it renders correctly and is easy to navigate on all devices

  • Ensuring HTTPS: this is a secure connection that protects users while browsing the internet, and sites without it - especially sites where customers can spend money - will be heavily penalised

🚩 If an SEO agency don't address any of the above, they may not have a good understanding of technical SEO or ranking factors.


Busy office with a hardworking young man sitting at his desktop computer in the foreground with his colleagues have a discussion over paperwork in the background

Create new content

This includes content for your website (service pages, information pages, blog posts, etc) as well as content for external sites (guest posts, articles, thought leadership pieces). Different industry voices place different importance on guest posting and other outreach-based content efforts, but ultimately it comes down to your goals and which activities are best suited to achieving them.

Content will be created in line with trends and topics that are relevant to your industry, and this will be informed by effective keyword research. Text-based content traditionally constitutes the majority of content created for SEO purposes, but other formats like video, audio, and infographics may feature.

🚩 If you don't feel an SEO agency is writing in your tone of voice, call them up on it.

Build links

Link building sometimes gets bad press for various reasons, but building quality links from relevant sources is still a cornerstone of a successful SEO strategy. An SEO agency will identify opportunities to acquire links from relevant industry sites, quality directories, and various other sources. The idea is to generate traffic from these sources by ensuring the link points to something that will deliver value to the reader.

Links also provide SEO signals, with the underlying assumption that a web page with many inbound links from high-quality, reputable websites must be of high quality itself. While search engines hold their cards close to their chest with regard to the inner workings of their ranking algorithms, good links have been correlated with rankings for a very long time.

🚩 If an SEO agency will not report on specific links they have built, they may be hiding less-than-ideal practices.


Both of the above require active outreach to be successful: created content must be promoted, and maybe even hosted on external websites; links must be arranged through contact with somebody at the target website or publication.

An SEO agency may undertake outreach on behalf of your company to promote the content they have created, and to build links. If this is the case, look to understand whether they will do this as your company, or on behalf of your company. If the former, be very sure that you are happy with their understanding of your brand tone and guidelines.

🚩 If an SEO agency will not show you their outreach targets when asked, they may be planning to contact low-quality, irrelevant sites.

Monitor brand mentions

SEO agencies may set up alerts for your brand and associated terms to leverage any natural coverage. This could be as simple as asking for a link from an article that mentions your brand without linking, or as involved as making efforts to have critical, defamatory content removed.

The latter moves toward reputation management, which is traditionally a separate service to SEO, but there can be overlap.

This is also a way to keep their fingers on the pulse, and to refine their understanding of the online profile and positioning of your business.

🚩 If an SEO agency do not catch negative mentions of your brand before you do, ask about their monitoring tools.

Monitor results

SEO needs constant vigilance to be effective. Google updates its algorithms frequently, competitors move around in the rankings according to their marketing efforts, and your business will create collateral that needs to be optimised and incorporated into your wider SEO strategy.

An agency uses a range of tools and techniques to monitor rankings, traffic, engagement, user journeys, and conversions. This monitoring serves two purposes: first, it confirms whether existing work is having the intended results; and second, it provides insights to be taken forward to increase the effectiveness of future work.

🚩 SEO is not a case of fire and forget: if your agency never update you on the progress of their efforts, ask them why.


Financial paper charts and graphs on the table

Report on results

An agency should provide information on the metrics associated with all of the goals identified during onboarding. This could include:

  • Visibility: rankings, new search queries, etc.

  • Traffic: page views, bounce rate, etc.

  • Leads: enquiries, engagements with CTAs, etc.

  • Conversions: amount, rate, etc.

  • ROI: value of conversions, etc.

This should be accompanied by commentary from the agency, explaining what has happened and why, as well as insights to be carried forward in the campaign.

🚩 If reports never materialise, or if they are just a few meaningless stats without commentary, ask for more.

Those are the activities you can expect. Here's a rundown of a few popular SEO tools that an agency might use:

  • HubSpot: a comprehensive marketing platform with tools for all sorts of SEO activities, from content management and website analytics, to responsive page design and CTA creation.

  • Screaming Frog: a tool that analyses links, images, meta data, and scripts on a website.

  • Google Keyword Planner: a tool that gives search volume for keyword terms, and recommends similar terms around given queries.

  • Google Analytics: a platform that tracks all engagements with your website, giving hugely detailed insights on user journeys and behaviour.

  • Ahrefs: a link research tool which gives information on website backlink profiles

An SEO agency does not have to use all of those tools to be legitimate: there are tons of tools and techniques, and each agency works with a different toolkit. In the same way, not every SEO strategy will include all of the areas we outlined above.

What should be consistent is an ability to deliver results, the knowledge required to do so, and the responsiveness to be up to speed with industry developments and how they impact your website.


Note: an agency who do SEO may not market themselves as an SEO agency. They may use a term like digital marketing agency, or the even broader marketing agency.


In another article we explored signs you may need to work with a digital marketing agency. Your business not achieving the five outcomes at the start of this piece (visibility, traffic, leads, conversions, and ROI) are the first signs. You can read the article for some others.