Google processes over 40,000 search queries every second. Over the years, it has continually perfected its content filtering and ranking algorithms to deliver the most relevant information to users precisely when they need it.
For that reason, simply owning a website isn’t enough to reach your potential customers. You must optimize your website for Google’s crawlers and rank on the first page of the search results pages (SERP) to capture organic traffic.
There are two ways to do that: through search engine marketing (SEM) and search engine optimization (SEO).
In the next sections, we’ll answer explore what SEO and SEM are, respectively, and elaborate on their similarities and differences. Finally, we’ll compare SEO vs. SEM to help you decide which strategy to invest in.
Table of Contents
What Is SEM?
Search engine marketing or SEM is the practice of using paid ads to feature your web page at the top of search engine results pages (SERPs). SEM campaigns are based on a keyword bidding system. Using Google Ads (previously known as Google Adwords), top SEM agencies bid on targeted keywords. The highest bids, combined with the best optimized SEM campaigns, can secure you the top positions for these targeted keywords.
Now, notice we said, "the highest bid combined with the best-optimized campaign" because simply buying an ad won’t do you any good. You still need to invest time and effort into finding the right keywords, optimizing your landing page for relevance by ensuring your content aligns with users’ search intent, and refining the ad following Google’s guidelines and best practices.
These are the elements that go into SEM campaign building:
Keyword Research
Keywords are the terms users type into search engines to find the content they’re looking for. Some keywords are informational, such as definitions and guides. These are typically used for blogs that work best as top-of-the-funnel content, so not the ideal choice for ads.
The best keywords to choose for ads are those with transactional or commercial intent.
To find these, think about what your prospects might type into the search engine when looking for products or services in your domain. Keywords that include "buy," "discount," "deal," "coupon," and "free shipping" are good examples.
We’ll discuss keywords in more detail later in this search engine marketing vs. search engine optimization breakdown.
Ad Copy
Once you have the relevant keywords, it’s time to create an ad copy. Your ad copy should be valuable and engaging enough for target users to click on.
The ad title and meta description should correspond to the user’s search intent and ideally highlight your offering or unique value proposition(s). The display URL should be simple, in line with the title, and includes your target keyword.
To optimize performance, note that Google allows you to define multiple versions of your ad titles and descriptions.
Ad Auction
Once your campaign is ready, it’s time to bid on the target keyword(s). Here’s how it works:
Every time someone enters a search query into Google, the ad auction process starts. Advertisers that want to take part in it will identify keywords they want to bid on and state how much they are willing to spend per click.
However, not every bid guarantees ad placement in the search results. Google uses two main ways to determine whether your ad shows up on the SERP: maximum bid and Quality Score.
The maximum bid is the approximate amount you’d pay for a click. If this amount is greater than your competitors, your chances of ranking at the top increase.
The Quality Score is a metric that evaluates the quality of your ad, including how well it matches the search intent for the keyword it is targeting. Ads with higher scores enjoy an advantage over other bidders and their cost per click (CPC) even goes down. For that reason, the most important thing when it comes to ads is their quality.
Now, let’s move on to the "SEO" part of the SEM vs. SEO overview.
What Is SEO?
SEO is the practice of optimizing your website content guided by target keywords to make it more visible to search engine crawlers and improve its chances of ranking on SERPs through non-paid (organic) methods.
From this, you can already see the biggest difference between SEO and SEM: SEM involves paid ads, while SEO relies on optimized content and is (theoretically) ranked purely on “merit”.
A big part of SEO is knowing your target audience and the search intent behind the query. In other words: What is it they want to find when googling this keyword? What type of content? What information? And even related or follow-up questions they might have.
While content is the key pillar of optimization, SEO is, in fact, composed of three components:
- On-site SEO
- Off-site SEO
- Technical SEO
If you’re unfamiliar with any of these components, here’s an explanation:
On-site SEO
On-site SEO involves optimizing the content and HTML source code of a page or entire website.
The core of on-site optimization is high-quality content. No matter how easy a keyword is to rank for or how many links point to your page, if users aren’t spending time reading your content and are returning to the search engine for other results, you won’t rank for long.
That’s not to say that keywords don’t matter — they absolutely do! But the way SEO vs. SEM optimization for keywords works is a little different.
Unlike SEM, SEO is a long-term approach and needs time to produce results, so experts must be strategic in choosing their keywords. For example, ranking high for one-word keywords such as “shoes” or “bikes” is difficult because there are a lot of companies that sell them online. Many of them, such as Jimmy Choo or Louboutin, are well-known brands so they tend to have an advantage over competitors. You simply won’t stand a chance against them, at least not in the beginning.
For that reason, it’s best to target long-tail keywords, which are typically more specific and thus receive less traffic and face less competition. Improving your search engine positioning is much easier with long-tail keywords. Of course, you’ll still need to make sure they are relevant to your business and that users are interested in those topics.
When optimizing content for SEO, include your target keywords in the title, headings, and meta description, and throughout the content where they fit naturally.
Aside from keywords, internal linking is another effective technique used by SEO companies. This involves linking to related and relevant pages on your website, so crawlers can easily discover new content. Moreover, it improves the user experience by offering them additional insights.
Off-site SEO
When discussing the difference between SEO and SEM, it’s impossible to skip off-site SEO. While search engine marketing activities are done solely on your website, off-site SEO, as the name suggests, happens outside your website.
Off-site SEO includes activities aimed at increasing the number of websites that link to your content. The goal is to improve the search engine’s perception of your site's popularity, relevance, trustworthiness, and authority through links.
The best off-site SEO is when someone adds the link to your website without any intervention on your behalf. For instance, a blogger mentions your products or your content simply because they love it.
It can also be deliberate, through link-building activities with influencers or guest posting.
Technical SEO
Technical SEO refers to optimizing your website’s code and other technical elements to make content discoverable, accessible, and readable to search engines.
How Are SEM and SEO Similar?
Before we get into the key SEO vs. SEM differences, let’s look at some of their similarities.
They Share the Same Goal
The first thing SEM and SEO have in common is their goal: they both aim to grow your business and increase website traffic.
Now, while they’re two sides of the same coin, they do have different approaches. Search engine marketing relies on paid ads to convert users into customers, while search engine optimization uses non-paid techniques to achieve organic results.
Both Rely on Keywords
As we’ve already mentioned, both SEM and SEO use keywords to reach the top of the SERP. Their main premise is to connect with users by providing solutions and answers to their queries and funneling them into your website.
The Quality of the Copy Comes First
As we’ve already established, you can never make up for bad content — no amount of optimization, best practices, or links can do the trick.
Why? Because Google “observes” searchers’ behavior on your webpage. If they leave after a few seconds and return to the search engine to explore other results, it signals Google that your content has failed to meet searchers’ expectations.
Therefore, every blog you write and every landing page you create must bring value to the users.
4 Key SEM And SEO Differences
Although both focus on driving quality traffic to your website via search engines, there are several search engine marketing vs. search engine optimization differences.
1. SEO Is (Theoretically) More Affordable
As you know by now, SEM uses pay-per-click ads to place your content at the top of the SERP for targeted keywords. Each time a user clicks on your advertised link, you are charged a fee.
So, SEM has very clear costs involved, but there are ways to lower them. We’ve already seen that high-quality ads rank better for lower investments. However, optimizing your ads and the linked page(s) requires time, which can represent additional costs.
SEO, on the other hand, is free — at least nominally.
Optimizing your content using SEO techniques is indeed free. Google doesn’t charge for SEO. But you do need to create high-quality content, optimize it, run technical audits, apply fixes, build links, etc. And that’s the catch — these things also don’t come for free.
First, to find viable keywords, you need a keyword research tool. While most of these tools have a free version, premium versions will allow you to see more keywords, assess their difficulty, know the monthly search volumes in target geographies, and so on. Ahrefs Keyword Research Tool, for instance, starts at $119 and goes up to $419 a month, depending on the included features.
Also, high-quality content creation, technical optimization, and link building don’t come for free. You’ll need an experienced content company, an SEO specialist, and possibly outreaches to ensure the content is fully optimized.
As you can see, SEO isn’t actually free; it just has no fixed costs.
2. Results Are Faster With SEM
When talking about SEO vs. SEM in terms of timeframes, SEM definitely has the upper hand here, as SEO takes time to work.
A newly created website may take up to 4 weeks to be crawled and indexed by Google. However, it doesn’t end there. Research conducted by Ahrefs shows that it takes 3-6 months for SEO efforts to yield results. And that’s understandable, taking into account the various actions involved, from building credibility with Google to creating content and fixing any SEO issues that may arise.
On the other hand, SEM is almost immediate. From the moment an ad is approved to when it starts showing up in search and driving traffic to your website, you’re looking at days if not hours.
3. SEO Delivers Long-Term Value
While SEM may work faster than SEO, there’s something to be said about longevity in the SEO vs. SEM debate.
Sure, SEO does take some time to show results, but once it does, you’re likely to stay in your position over time without significant investments in maintenance. SEM, on the other hand, works only while you’re paying for it. Once you stop, you’re back to where you started traffic-wise. Also, contrary to belief, SEM is not a quick solution to fixing your SEO.
Of course, this doesn’t mean you can’t do both SEM and SEO at the same time. You can start with a SEM campaign while optimizing the rest of your content for SEO in parallel.
4. SEM Has a Lower Click-Through Rate
Click-through rate shows the percentage of people who click on your link from the SERP. This metric is very important for both SEO and SEM. This is where SEO dominates the search engine marketing vs. search engine optimization debate.
As many as 70% of online marketers state that SEO is better than SEM when it comes to generating sales. This may have something to do with the user’s lack of trust regarding paid ads.
Should You Invest in SEM or SEO?
As you can see, the difference between SEO and SEM is big. Deciding which one you’ll use and if you’ll combine them depends on several factors.
Types of Keywords
We’ve already mentioned that SEO is best for long-tail keywords, while SEM is most effective with more competitive, typically short-tail keywords. But there’s something else you should know when it comes to keyword types.
Informational keywords, such as ’how-to’ blogs, perform better with SEO than SEM. This is because you don’t want to waste too much money on people who are there to learn, not buy. Most of them won’t purchase your products, but they will help you build and improve brand awareness.
Time
If you’re in a hurry, you’re better off using SEM. It takes time to create enough content and optimize it in a way that brings results organically. SEM works as soon as you enter the ad auction.
Budget
If you’re a small business owner or a startup, you probably have a limited budget for advertising. As Google ads can be pretty expensive to drive results, especially if you don’t have the best copy, you’ll probably want to focus on SEO, understanding that it is a long game.
Skills
SEM requires knowledge of keyword research, copywriting, and platform-specific best practices. But so does SEO. Understanding the basics of SEO is key to successful SEM as it requires proficiency in keyword research and landing page optimization.
This is why it is typically advisable to start with SEO. You won’t spend (much) money in the learning process, but you will acquire the foundational knowledge for both SEM and SEO.
Takeaways on SEM vs. SEO
Hopefully, this SEO vs. SEM comparison helps you understand these two practices a bit better. Both can help you increase your website traffic and acquire new customers via search engines.
Besides their many similarities like their shared channel — search engines — and reliance on keywords, the main difference between SEO and SEM is that SEM aims to acquire paid placement while SEO aims to acquire organic placements for target keywords on SERPs.
To ensure a comprehensive approach to your search engine strategy, consider finding digital marketing agencies that provide both SEO and SEM services.
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