SEO vs. SEM: What’s the Difference?

SUSO 26 July 2022

While both SEO and SEM are essential for any digital marketing strategy, they have different approaches. Read on to learn the key differences between the two methods.

Author: Ewelina Baczek, SEO Specialist

Ewelina Baczek

The lines between SEO and SEM are somewhat blurred – with this article, we hope to clear the smoke. Both methods have significantly reshaped online marketing over the last several years, and in fact, the two have become more entwined as businesses’ digital marketing efforts become more sophisticated.

The truth is SEO and SEM are two sides of the same coin; both can help your website get more traffic but in different ways. They both have their own set of benefits and drawbacks, which we’ll go over in this article, including the following: What SEO is and isn’t, what SEM is, how it differs from SEO, and why you need both.

SEO: What It Is and What It’s Not


SEO stands for Search Engine Optimisation, and it involves creating and optimising content on websites so that search engines like Google and Bing will display it at the top of their search results. This can be anything from blog articles to product descriptions, as long as it’s relevant and useful to their users.

However, just because you create this content doesn’t mean that your website will automatically rank at the top; there’s a lot more to it than that. Search engines use algorithms to decide which websites should show up for what keywords and these algorithms are constantly changing, which makes SEO a dynamic and ever-evolving field.

And when we talk about keywords, we’re referring to the words and phrases that users enter into Google or other search engines. These keywords are usually very general, like “chocolate” or more specific, such as “how is chocolate made”.

Search engines match keywords with web pages based on hundreds of ranking factors. For example, the quality of your website’s content, how user-friendly your website is, how often your website is updated with new content, and whether or not other websites are linking to yours all contribute to a page’s ability to rank for a particular keyword.

It is also worth mentioning that SEO is not only about optimising content for search engines. It also involves technical optimisation, which is referred to as technical SEO.

Technical SEO is the practice of creating and implementing a website’s technical elements in order to make sure that it is fully optimised for search engines.

Technical SEO is an important aspect of SEO, and it can have a huge impact on the website’s ranking on search engines.

What SEO Is Not

SEO is not a way to manipulate search engines so that your website ranks higher. Google and other major search engines will penalise, or even ban, websites they feel are engaging in SEO practices that violate their guidelines, which can include keyword stuffing and using link farms.

What Are the Advantages & Disadvantages of SEO?


  • Organic search is the main source of traffic for websites these days.
  • It can help you build an audience that’s interested in your products or services
  • Stay competitive within your target market
  • Build a better website and drive more sales
  • Build your brand’s authority and online presence
  • Measure and understand your target audience’s behaviour and use of your website through tools like Google Analytics and Google Search Console
  • It is cost-effective


  • You have to put in some time and effort to make sure your site is optimised for search engines so it will rank well on them
  • It can take a long time before your site starts showing up in search results
  • It takes work to keep up with Google’s ever-evolving algorithms, so it’s not always easy to stay on top of things

SEM: What It Is


Search Engine Marketing (SEM) is an umbrella term used to describe all forms of paid advertising on the internet. Examples of paid advertising methods include Google Ads, Facebook Ads, Pay-Per-Click (PPC), LinkedIn Ads, Twitter Ads, and Instagram Ads, just to name a few.

Like SEO, you can use SEM to generate traffic for your website. But, unlike SEO, you have to pay for it. Besides that, SEM uses different techniques than SEO to drive traffic to a website.

For example, you can use SEM to buy ad space on search engines like Google and Bing. You can also use SEM to bid on keywords related to your business. This allows you to show up in the first few results of a search engine’s results page (SERP).

What Are the Advantages & Disadvantages of SEM


  • It can help you reach a wider audience and increase your brand recognition quickly
  • It is a great way to complement your SEO efforts, as it can help you rank for related keywords
  • You can see how many people are clicking on your ads, which lets you measure the effectiveness of your campaign
  • It’s easy to set up and manage
  • It’s great for promoting specific products, sales, and promotions
  • It’s ideal for lead generation and collecting contact information from your audience


  • It is expensive as compared to other digital marketing channels like social media and email marketing.
  • It’s not ideal for highly seasonal products.
  • You need to be technical to understand how it works.
  • It’s more difficult to sustain a paid campaign compared to SEO.

The Differences Between SEO and SEM

If you’ve read this far, you already know the difference between SEO and SEM in terms of what they stand for and the basic mechanics of how they work.

But let’s summarise:

  • SEO is optimising your website for Google or other search engines to find it organically. This means making sure your site is of high quality and relevant to what people are searching for so that Google will rank it higher in its search results.
  • SEM is when you pay for your site to show up high on a search engine’s results pages. This can be done through paid advertising using Google Ads and other similar platforms.

In short, search engine optimization (SEO) is free (when you know how to do it on your own, and you don’t need the help of a specialist), while search engine marketing (SEM) is paid. 

But aside from this key difference and the mechanics of how they work, there are a few other major differences between the two.

Short Term vs Long Term

SEO is a long-term strategy that can have big rewards if done correctly. It takes time to work, but once it begins working, it doesn’t cost anything after the fact. All you have to do is make sure your site stays relevant and doesn’t drop in search engine rankings.

SEM is a short-term strategy that can get results faster but also costs money. The results are almost immediate, but it’s expensive and you’ll have to keep paying for the ads if you want to keep getting results.

Organic vs Ads

SEO is focused on getting traffic to your site from search engines. You want your website to show up in the top results for as many relevant searches as possible.

SEM is focused on bringing people to your site by buying ads with specific keywords. If someone types in a keyword you’ve bought, they’ll see an ad for your site before they see other search results.


SEO gives you less control over your results. This is because your results are also influenced by a number of external factors. You need to keep up with changes in search engine algorithms, and you learn a lot about what works and what doesn’t through trial and error.

SEM gives you more control over your results. But the key here is that you need a large budget and a specialist to really succeed.

So what does all this mean for your business?

SEO vs SEM: Which Is the Best for Your Business?

Knowing which strategy is best for your business depends on the type of business you have, the type of competition you face, your budget, your goals, and how much time and effort you’re willing to invest.

Here is a look at what strategy works for different situations.

Business Type

Local Businesses

If you have a brick-and-mortar business that relies on organic traffic from local searches, then investing in SEO is your best bet. SEM may work for some local businesses, but it will be more expensive, and the results will not be as long-lasting as with SEO.

Ecommerce Stores

Ecommerce stores should invest in both SEO and SEM because they need to show up in both types of search results (organic and paid). By doing this, they can reach a wider audience and increase their chances of getting sales.

Service-Based Businesses

Service-based businesses usually benefit more from SEM than SEO because people searching for their services are often ready to make a purchase. This is due to the fact that they have likely already done their research and just need help finding the right company.

Small Businesses

Small businesses should focus on SEO because they can’t compete with larger companies or big-name brands. SEO is an affordable option to help you get found in your area, and it also allows you to build trust with the community.

Large Businesses

Large businesses should focus on both SEO and SEM because they have the budget to do so. They can reach a wider audience with their campaigns, and they’re able to target specific demographics more effectively.


Startups should focus on SEO because they may not be able to match more established competitors’ budgets for paid ads. They need to build their online presence as well as their credibility and authority before moving onto SEM.


The level of competition in your industry will also play a role in deciding whether to invest more heavily in SEO or SEM. If you’re up against large businesses with sizable budgets and a well-established online presence, then investing more in SEM is likely necessary to stay competitive.

On the other hand, if your competition is still trying to figure out how SEO works, then you may be able to win more traffic and conversions with a good SEO strategy. Remember that it’s also possible to use both SEO and SEM strategies together. You could run an SEO campaign for long-tail keywords while running SEM campaigns for shorter, more competitive searches.

When to Use SEO vs SEM

There are certain situations where it is more advantageous to use one method over the other.

SEO should be used when:

  • You want to improve your organic search results
  • You want to target specific keywords
  • You have a well-designed website that’s easy to use
  • Your business is not location-sensitive

SEM should be used when:

  • You want to reach potential customers beyond those who are already familiar with your brand or website
  • Your goal is immediate visibility in the search engine results pages (SERPs)
  • You want to get the most from your marketing budget
  • Your business is location-based, and you want customers in specific areas

SEO VS. SEM: Why Every Website Needs Both

Whether you are a small business or a large enterprise, you need to have both SEO and SEM strategies in place.

Why? Think of it this way: no matter how big or small your company is, you want people to know about it and what you are selling. Having a strong presence in the search results will help them find your business when they search for the products or services that you offer.

But to achieve this, you need to make sure that your website appears as high up in the search engine results pages (SERPs) as possible. That’s where SEO comes in: by optimising your site for certain keywords, you can increase your chances of ranking higher in SERPs and thus getting more visibility for your business.

There are many facets to SEO, from the technical aspects of site architecture to the quality of your content. No single SEO tactic will be effective in isolation, and a holistic approach is necessary for success.

Holy Trinity Technical Content and Links

That said, SEM cannot work if you do not have a good foundation in SEO. This is because it relies on optimising websites for keywords and search results before running any paid ads. Without this optimisation, paid ads will not be as effective.

It’s for these reasons that every business should consider using both SEO and SEM as part of their digital marketing strategy.

To better understand why these two strategies work well together, let’s see how they help each other.

SEM Helps Increase Your SEO Rankings

One of the main benefits of SEM is that it can help improve your SEO rankings. By bidding on high-value keywords, you can get your website to appear higher on SERP results pages, which will naturally lead to more traffic and higher brand awareness over time.

SEO Helps Reduce Your SEM Costs

SEO can actually help reduce your overall SEM costs. This is because once you achieve a high ranking for certain keywords organically (i.e., through SEO), you no longer have to pay for ads every time someone clicks on them meaning more money is saved in the long run.

SEO Helps Improve the Quality of Your SEM Listings

The quality of your SEM listings is important to Google. The higher the quality, the more likely people are to click on them. This means that if you have good SEO for your website and business, it will help improve the quality of your SEM listings, making them more likely to be clicked on by searchers.

How To Invest In Both SEO And SEM

As we’ve already seen, both SEO and SEM are important for any website. And as a digital marketing agency that specialises in everything SEO so as to help our clients grow their online presence, we understand the importance of investing in both SEO and SEM.

This is why we recommend businesses invest in a professional SEO team like SUSO. We will be able to optimise your website with the most relevant keywords, clean up any errors, and ensure that you are using white-hat techniques throughout your campaign. This will help you improve your rankings and work to build a strong organic presence in search engines over time.

The same can be said for SEM. Search engine marketing is a complex and dynamic field, so unless you have the time to stay on top of it, your best bet is to hire an expert.

But what if you are on a limited budget and want to use both SEO and SEM for your business?

Then you have a choice to make. Depending on your industry, the competition for keywords, and the amount of time you have to work on your marketing campaign, you may be better off focusing on one or the other.

Final Remarks

It’s easy to get confused about the difference between SEO and SEM. Even if you’re an industry veteran, the constant updates on the practice of search engine optimisation make it hard to keep up with what does what, why it matters, and how it could impact your business. The same goes for search engine marketing.

But when you break down these two marketing strategies into their simplest form, you start to understand that they each serve a purpose in a larger strategy. While you have to have a grasp of the fundamentals of each, it’s even more important to know where they fit into your marketing strategy as a whole.

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