Check out the Neoreef blog for the latest industry insights and guides.

SEO vs. SEM: The Quick and Dirty Difference

What’s the difference between SEO and SEM? Different answers abound, but here’s our answer. If we do our job correctly, these explanations will make sense to you, and possibly even win you over.

Marketers, especially in the digital sector, are pedantic about terms and buzzwords. We love our alphabet soup. If it’s a three letter acronym like SEO, SEM, CRO, or PPC, someone has a strong opinion on what it actually means. This gets confusing because everyone has the strong desire to be right, but very few people agree on what these terms mean in the real world. 

As promised in the title, here’s the quick and dirty difference:

  • Search Engine Optimization (SEO) is the art and science of making sure Google understands your website, intended to achieve greater search engine visibility. 
  • Search Engine Marketing (SEM) is the practice of using paid advertisements in the search engines, intended to achieve greater search engine visibility and increase conversions. 

SEO is a must for any modern website, as it ensures your website is effectively communicating with search engines-- which allows people to find your website in the first place. SEO is done on your website. 

SEM’s goal also applies to search engine visibility, but directly intends to drive impressions and sales. SEM is done off of your website, usually through a service like Google Ads. 

Many marketers disagree with this assessment, because marketers are pedantic. But, you can now walk away from this blog post with a basic understanding of the difference. 

If you want to learn how they work together and affect your business’ overall marketing goals, then keep reading. We can go beyond the basics. Not too far, though, as we’re both busy people. 

What is SEO?

SEO Helps Google Understand Your Website; is Part of Being a Good Citizen on the Web. 

Other than the cost of labor, knowledge, and other resources, SEO is free. That means it’s not free at all, but you don’t need to pay a search engine to achieve greater visibility through SEO. You just need to put in the work and go about it the right way. 

SEO is the way we help search engines understand our websites. We give them information through our content, URLs, titles, image alt tags, meta descriptions, and other website components. When a search engine like Google crawls your website, the information you provided helps it understand what you do and which search terms are relevant to your website. 

If your businesses’ website is all about watchmaking, no matter how it’s optimized, you’re not going to show up in search results for “cat food.”

If your watchmaking website is poorly optimized, it’s not going to show up in search results for “watchmaker near me.”

If your website is properly optimized, there’s a good chance it will show up in search results for “watchmaker near me” and “best watchmakers.” 

Here’s a great, simple definition of SEO from Webopedia

SEO is short for search engine optimization. Search engine optimization is a methodology of strategies, techniques and tactics used to increase the amount of visitors to a website by obtaining a high-ranking placement in the search results page of a search engine (SERP) — including Google, Bing, Yahoo and other search engines.

It is common practice for Internet search users to not click through pages and pages of search results, so where a site ranks in a search page is essential for directing more traffic toward the site. The higher a website naturally ranks in organic results of a search, the greater the chance that that site will be visited by a user.

SEO goes beyond just “being seen on Google,” though. SEO means being a good citizen of the web. SEO should benefit the user as much as it benefits the search engines. When you optimize your website, you’re helping the right audience find the information they need. You’re also fighting spam, and keeping irrelevant content out of people’s search results. 

SEO isn’t just about helping people find your website-- it’s about helping the right people find your website. 

As it turns out, SEM is about helping the right people find your website, too. But it takes a different approach. 

What is SEM? 

SEM is Search Engine Advertising with Valuable Metrics and Verifiable ROI.

SEM isn’t free in any sense of the word. 

When we refer to SEM, we like to keep it simple. SEM refers to pay per click (PPC) advertising, usually done through Google Ads. There’s no way to claim PPC is the only method of search engine marketing, but it’s usually what we mean when we say SEM. 

If you write a good ad campaign, target your ads to relevant consumers, and provide a great landing page on your website, then you’re primed for search engine visibility via SEM.

If you know what you’re doing, SEM places ads above Google’s organic search results. It also places them below, and in other locations around the search engine results pages (SERPs). That means that if your ads are firing on all cylinders, you’re guaranteed to capture the attention of your target audience within the search results. 

It’s breathtakingly effective at getting eyes on your website and generating leads. 

More importantly, it can also make you money. And, unlike traditional advertising such as billboards and radio spots, the ROI is absolutely measurable. 

Here’s the ROI formula for Google ads, straight from Google itself: (Revenue - Cost of goods sold) / Cost of goods sold

And, a concrete example right from Google’s help pages:

Let's say you have a product that costs $100 to produce, and sells for $200. You sell 6 of these products as a result of advertising them on Google Ads, so your total cost is $600 and your total sales is $1200. Let's say your Google Ads costs are $200, for a total cost of $800. Your ROI is:

    ($1200 - $800) / $800

    = $400 / $800

    = 50%

So, SEM really can be like putting a dollar in the marketing machine and getting two dollars back. A PPC ad campaign gives you all the metrics you need to decide if your SEM efforts are worth the money, and there’s no guesswork involved. 

But, for SEM to work properly, your website needs to be optimized. If you ignore your SEO, then SEM isn’t going to do you much good at all. If Google can’t understand your website (and if Google thinks a user can’t understand your website), or even understand your ad’s landing page, then your ads won’t show up in the top positions in the SERPs. This relates to quality score and ad rank. If your ad rank is low, your ads may not show up at all. Even if you’re paying.   

SEM also grinds to a halt the moment you stop paying for it. If you properly invest in your SEO, however, it will organically send visitors to your site with no continuing payments necessary. 

SEM can’t work effectively without SEO, and SEM doesn’t affect SEO at all. It’s a one way street. 

From Google:

Advertising with Google won't have any effect on your site's presence in our search results. Google never accepts money to include or rank sites in our search results, and it costs nothing to appear in our organic search results. Free resources such as Search Console, the official Webmaster Central blog, and our discussion forum can provide you with a great deal of information about how to optimize your site for organic search.

SEO and SEM do interact with one another. They have to, as they’re both intrinsically related to search engines. So, how do we categorize them? Which one falls under which umbrella?

Is SEO Part of SEM? Are SEO and SEM Both Part of Search Marketing? Are SEO and SEM Totally Separate?

Now, we get back to pedantic marketers, their acronyms, and their need to categorize everything. Pedantry comes from passion, though, so no judgement here.  

Many people say that SEO is a part of SEM. From their perspective, SEO is part of your overall SEM efforts, because visibility is always a part of marketing. 

Others argue that both SEM and SEO fall under the umbrella of “search marketing,” but are different practices. 

So, who’s right? It’s impossible to say, but there’s an easier way to think about it. 

SEO doesn’t fall under the SEM umbrella because SEM can’t exist on any effective level without SEO. 

Saying that both “SEO and SEM” fall under the “search marketing” umbrella just creates more questions, simply because SEM itself stands for search engine marketing. We’re here to answer questions, not spread confusion. 

So, which umbrella do SEO and SEM fall under?

SEO and SEM both fall under the umbrella of “your marketing budget.”

SEO and SEM are by no means the only two elements of your digital marketing budget. Think of them as columns that support your marketing acropolis-- you need more than two columns to support the structure. You might also be engaging in content marketing, social media, video marketing, and traditional marketing. They all just fall under the greater “marketing budget” category. 

If you care about your website, then you have to at least spend some amount of time and resources on SEO. You want your website to show up in search results, and applying SEO fundamentals helps Google understand what you do and who you’re trying to serve. There are plenty of SEO agencies who make bogus claims and promise outrageous results, but you can ignore them. Focus on the SEO fundamentals and ignore the snake oil. 

SEM is an effective use of marketing dollars. It’s worth making room in you marketing budget for an effective PPC campaign. Those clicks, leads, and sales go away once you stop paying to run ads, though. And your ads won’t get the results you want unless your website is optimized for search. 


It’s worth making room in your marketing budget for both SEO and SEM. SEO is critical to the overall success of your website, and SEM can deliver devastatingly powerful results. But they are different disciplines that approach search engine visibility in two very different ways and, as we mentioned earlier, it’s a one way street. 

If you read this entire post instead of stopping at the “quick and dirty difference,” you understand SEO and SEM better than you did before-- even if you choose to categorize them differently than we do. 

No matter how pedantic we are about the acronyms themselves, we can all agree that both SEO and SEM are worthy components of your marketing budget. 

Powerful Tools, Unlimited Support

Neoreef addresses the two biggest issues with websites: lack of control and lack of support. We enable easy control of your website, while a dedicated support team provides you with training, mentorship, and specialized skills.

Start Your Project Today