What is SEO? The Three Pillars of Search Marketing

SEO, or Search Engine Optimisation, is a combination of digital marketing techniques focussed on increasing the visibility of a website in search engine results pages. For most people this means getting on page one, or even position one, in Google’s search results. Perfectly implemented SEO combines technical website development, content marketing, user-experience, and even paid advertising. These aspects can be further categorised into three primary areas, or pillars.

The three pillars of SEO are technical SEO, on-page SEO, and off-page SEO. Each pillar has a vast depth to be plumbed, and could easily be a full-time job for one person. In fact, most enterprise level businesses have entire teams of SEO experts fighting for their rankings.

three pillars of seo like roman columns in the sun

In this article I’ll go through each of the three pillars of SEO and explain their unique requirements. Each pillar provides a unique challenge and will require the implementation of different skill sets in order to optimise effectively.

Let’s dive in. Careful though, it’s deep.

What is technical SEO?

What is on-page SEO?

What is off-page SEO?

What is technical SEO?

Technical SEO is the optimisation of your website’s code and structure. It requires a strong website development skill set. Technical SEOs need to be adept at website development at every level from the CMS down. They’ll handle your HTTP, examine your ccTLD, and bang out some FTP.

Here’s a list of the main technical website optimisations, also referred to as ‘stuff you can do better on your website’:

Broken stuff

Broken website stuff sucks for SEO. A website needs to be inspected for:

Broken links – Ever click a link and get a ‘Not Found’ error splash up on the screen or the number ‘404’ or ‘403’? Thats bad for the search engine user experience, and so it is bad for SEO.

Broken images – They’re just plain bad for everyone. They’re a waste of time for users and search engines alike.

Broken, blocked, endless, chain, max, or temporary redirects – Redirects from one page to another must be done correctly. They can go wrong very easily.

Broken tags – Hreflang tags (used on websites with multiple languages) for example, must be implemented correctly. Your html needs to be up to snuff with no broken…or missing stuff.

Missing stuff

You can’t be missing crucial stuff on your website. Make sure you watch out for:

Missing or empty title tags – Title tags are often the words used when your website shows up in search engine results. Be sure to write good ones.

Missing or empty description – A meta description is the paragraph displayed underneath your main title tag. This is your chance to convince someone to click.

Missing words – Having one or two word descriptions for things just isn’t good enough. This applies to title tags, descriptions, and SEO in general.

Missing or Empty H1 – The most important sentence at the top of your page must be wrapped in an tag.

Missing robots.txt – Block robots from accessing certain parts of your website with your very own robot, Robots.txt.

Missing images ALT attributes – Add info to your images to improve your image search results, and assist visually impaired users.

Missing protocols – You need modern, secure, internet protocols when owning a website.

Missing markup – Use JSON – LD schema markup to show up in a variety of search result formats.

developer working on a website

Duplicates & multiples of stuff

Try not to have the exact same stuff in more than one place on your website. Search engines can tell when you are copy-pasting large sections of text without rewriting it for a separate page.

Duplicate websites – Accidentally cloning your website is surprisingly easy. Two common problems exist:

  1. Not automatically redirecting all your pages from http, to https.
  2. Not automatically redirecting all URLs missing a backlash at the end, to one that does end in ‘/’.

Duplicate pages – Clones of individual pages still occur for many other reasons. There can be only one.

Duplicate titles & descriptions – Create a unique page title and description for every individual page on your website.

Multiple titles & descriptions – Having multiple page titles and descriptions just makes things harder for Google. SEO is about making it easier.

Multiple H1 – An H1 heading on your webpage should be a clear statement of what the page is about. 

Duplicate H1 – Google gives the H1 more importance than other headings, only having one makes things even clearer.

Duplicate Canonical URLs – The ‘rel=canonical’ tag is used to signal to Google the definitive URL of that webpage. Again, having only one keeps things simpler for Google.

Structural stuff

The way you build your website is very important. The format of your URLs should be clean and orderly. Products need to be in categories, and your page tree properly organised. You also need to look at:

Max URL length – The optimal URL length is between 50 – 60 characters.

Missing internal links – Linking between pages on your website helps Google crawl your site more efficiently.

Internal nofollow links – Adding a ‘nofollow’ tag to your internal links means crawlers will believe them to be unimportant. That’s usually a bad move.

5xx error pages – Error codes starting with a five indicate a server error. This means something on your end is broken.

Long server response time – Speed is extremely important for SEO. The faster your servers, the better.

Bad AMP HTML format – Your website needs to be coded in such a way that it works well on any device.

Security – The security of your site is another SEO consideration. HTTPs is a must, at minimum!

Big stuff

There is such a thing as ‘too big’ when it comes to websites. There is an optimal size for everything. Keep your site blazing fast and you’ll outrun your competitors.

Max image size – Huge images on your website will slow it down. A slow site is an un-optimised site.

Max title length – If your page titles are too long, they may be truncated in search results.

Max description length – The same goes for descriptions. Google will show 920 pixels (about 158 characters) on desktop, and around 680 pixels (120 characters) on mobile.

Max H1 length – One sentence, or 20-70 characters, is ideal.

Max HTML size – Having too much unnecessary HTML on your site will only serve to slow it down.

Page size – A bloated web page will load slowly. Keep things as trim as possible while still serving the purpose of the page to the fullest.

Code compression – Code should be compressed as much as possible to help overall speed.

Solid technical SEO requires someone who isn’t going to cut corners, is willing to follow best practices, and has the proficiency to sufficiently optimise their code. A skilled developer will make all the difference to your technical SEO efforts.

website with design work going on

What is on-page SEO?

On-page SEO is the optimisation of everything a user can see on your website. Text, images, buttons, videos, everything someone can view or interact with on your site can be optimised.

For someone to implement on-page SEO they need to be comfortable operating in the CMS of a website. A technical skill set is still advantageous for on-page, but strong copywriting skills are essential and an eye for design comes in to play as well.

On-page structure

Just like the structure of your website matters for SEO, so too does the structure of your on-page content. Here are the basic things to consider:

Optimisation of the title tag – This is the title of your search result. It pays to write something convincing.

Optimisation of meta tag description – This is the description underneath the title of your search result. Again, writing a good one is going to encourage traffic.

Word count – Google favours content that answers the user’s search query. This can’t be done in a couple of sentences. Try to hit 1000 words per page. 

H1-H6 headers optimisation – Header tags each have their purpose. They need to be optimised and used correctly.

‘Breadcrumb’ implementation – Ecommerce sites should have breadcrumb links to help users (and search engine crawlers) navigate the site.

Internal links optimisation – I’ve already mentioned the importance of including internal links. Knowing where to put them is a big part of on-page SEO.

No hidden text – Hiding text in an attempt to manipulate rankings is an old practice that you won’t get away with anymore.

Image optimisation – As well as shrinking file size with technical SEO, image alt-text and filenames can be optimised as well.


The way users engage with your website signals to Google how worthy your website is to rank. The more that users engage with your site, the higher your chances of ranking at number one.

Fulfill the search query with your on-page content and keep people on your website. It’s a sure-fire way to get your page ranking. Here’s a bunch of engagement factors to look at:

CRO Conversion Rate Optimisation is the art of convincing users to click. The goal of your site is called a conversion, whether that be buying a product, downloading a file, or submitting their details. The better you get at convincing people to click, the better you will rank.

website sign up form

Blog articles – A blog is the key to developing SEO in the long-term. Write good articles based on keyword research around what people are searching for, and you’ll be rewarded with traffic.

Question & answer sections – Users are often searching for the answers to their questions. Provide these answers, and search engines will notice.

Fresh content – Having up-to-date reading material is better than having old, stale, irrelevant content. Keep posting new content often, and you’ll stay relevant.

Formatted structured content – A big block of text with no structure is going to be hard for someone to read, and they’ll likely look elsewhere. Be sure to have a clear heading, introduction, subheadings and conclusion.

Photos and infographics – Users respond to visual content. Make sure to use images to break up text, and display factual content in infographics wherever possible.

Grammar and spelling – Don’t make mistakes! Whether the user notices or Google does, it’s not going to be good for your ranking.

Unique copy – Plagiarism is bad in every shape and form. Google will know if you’ve copied another website, so make sure your website content is unique.

Sharing – Users sharing your content is a great signal to Google. Make sure you give them the ability to with social sharing buttons.

Time on page – The amount of time a user spends on your website is the ultimate measure of engagement. Keep users on your site for longer than your competitors, and you’ll be likely to outrank them.

Commercial factors

Every business needs a website. If your commercial venture  is going to be successful online, you’ll need to make sure you include the relevant information to help with SEO. Make sure you include the following pieces of info.

Wide range of products – If you’re selling products, it’s a no-brainer to have them all listed on your website. Detailed item descriptions and high-quality images are a must.

Delivery & payment options – Include everything a potential customer might want to know about payment and shipping.

Customer support – Clearly show your customer support options. Live chat, contact information, and FAQs are all good signs.

Credit options – If you offer credit options, be sure to include this information in a clear manner.

Warranty and returns – Displaying your warranty and return information will boost customer trust and reduce the amount of customer support enquiries.

Access to cart – For ecommerce sites, make sure the shopping cart is available from any page the user may be visiting.

Legal details and licenses/certificates – Make sure to have a page featuring your terms & conditions, privacy policy, and any other legal information you need available to your customers.

Registration through social networks – People don’t like having to make new accounts for every website they use. Allowing people to register with their existing accounts like Facebook or Google is easier for users, and increases their chances of becoming a customer.

Geo-options – If you offer your products or services in multiple countries, your website should reflect it. The ability to serve different information to users based on their location is priceless. Currencies, shipping costs, and even products can be tailored to your users.

Email on website’s domain – It may seem obvious, but having your business email addresses on the same domain as your website is essential.

Accounts in social networks – Being present on the same social networks as your potential customers is a requirement these days. Linking back to your website from social media and vice versa will help boost user engagement.

On-page SEO is all about what the user sees, reads, and interacts with on your website. The ability to stand out and be unique is advantageous, but familiarity with the site structure and ease of use is equally important. On top of that, being able to convince visitors to interact with your website sends a strong signal to Google that you’re worth ranking #1.

stack of magazines feat. bon appetit

What is off-page SEO?

Off-page SEO covers everything you can do to improve your search presence that doesn’t involve changing your actual website. It’s combination of content marketing, creative marketing, and PR.

Content marketing – Good content is better than bad content (or god forbid, no content), but can only get you so far. Creating great content will lead you to page one.

Link building – Convincing others to link to your content will help secure a podium finish in search engine results pages (SERPs). The more websites that point to your site, the more Google sees it is as deserving of a high ranking.

Crowd-marketing – Using existing influencers of social networks is a great way to draw in crowds of followers. Whether this occurs online via social media or through in-person events like sponsored run clubs, it’s a basic principle in marketing to target many people in one campaign.

Brand awareness – All your marketing campaigns contribute towards an immeasurable marketing statistic known as ‘brand marketing’. Considered a vanity metric by some, it really exists as more of a general vibe about a brand. To put it another way, what percentage of your total target audience do you estimate would recognise your name?

Local SEO

Whether you’re a local business or just capable of serving a specific location, local SEO is less about being ‘local’ and more about the ‘locality’ you want to target. If you have a retail location, the items in this list are a must.

Google My Business – Submit as much business information as possible, get a postcard from Google in the mail, and show up in local search. This is literally the first step in SEO after building a website.

Geo setup in Google Search Console – GSC allows you to easily serve Google information about your website. Make sure you let them know which country you’d like to target!

Google Shopping – Sell online? Look, here’s a video on setting up your Google merchant account:

Reviews & case studies – Everybody finds recommendations from people in the same location more convincing. It gives your brand a sense of familiarity.


Paid advertising is an entirely separate discipline to SEO, but needs to work synchronously. PPC campaigns can inform SEO campaigns, and vice versa. Having these people working closely is only going to be beneficial to them both.

For small to medium websites, waiting for organic traffic to test CTR can take months. Use the (often larger) budget of paid marketing to quickly test converting copy in ad headlines and descriptions. Small tweaks over time allows you to fine tune your search result listings.

The secret pillar of SEO

Now you’ve either read this entire list of optimisations, or you’ve impatiently jumped to the bottom to see how it ends. Either way, you’re about to learn about the fourth pillar. “But the blog’s called ‘The Three Pillars’!” I hear you cry. This is true, and I still stand by my statement that the three pillars of SEO are technical, on-page, and off-page. Here’s the thing though…you’re in an SEO pillar right now.

woman hiding behind pillar of seo secretly and suspiciously

Pillar pages – A pillar page exists on a website in order to cover a broad topic in greater detail than anywhere else on your site. It acts as a hub, close to the homepage, that can link out to other internal pages. This helps both search engines and users navigate your site. 

See also: this very page.

Subscribe to the SEOwriter blog: