SEO vs SEM: What’s the Difference (and Which is Better)?

Kayla Mackie Senior Digital Outreach Specialist
Key Points
  • SEO is the process of optimizing a website to bring in traffic from organic search.
  • SEM relies on pay-per-click (PPC) advertising platforms to deliver website traffic.
  • Implementing both digital marketing channels can elevate brand awareness, increase site traffic, and drive greater revenue.

When you plan your marketing budget, your primary goal is to deliver the strongest growth for the lowest cost. When you allocate funds to grow revenue through your website, you need to consider both short-term gains and long-term profitability. In other words, you need to weigh SEO vs. SEM.

Of course, we all know it’s not as simple as one versus the other. So, what’s the perfect mix? How do you cash in enough of your coins on SEM to hit your immediate goals without draining your funds and hindering future growth?

To make the most informed marketing decisions, you need to understand the strengths and weaknesses of SEO vs SEM.

Obviously, the biggest difference is that SEO is an unpaid (or organic) marketing channel while SEM is a paid marketing channel. Both can play a powerful role in reaching your target audience, improving brand visibility, and growing website traffic.

However, to maximize your marketing results, you need to know when to use SEO vs SEM.

What is search engine optimization (SEO)?

Search engine optimization (SEO) is the process of increasing organic (non-paid) visibility in search engines to improve brand awareness and drive targeted users to your website. SEO requires an optimized website as well as a thoughtful off-site strategy.

The Google Search algorithm ranks web pages based on hundreds of different signals. These ranking factors include high-quality content, good page experience, links, and much more. Ultimately, Google aims to provide searchers with the best answers to their queries.

To compete effectively in the organic search engine results pages (SERPs), it is important to implement some of the core SEO techniques outlined below.

On-Page SEO

On-page SEO is the process of optimizing the elements of a single web page to help search engines understand what it’s about. It also ensures that your content aligns with user expectations, including keyword intent, format, and comprehensiveness.

In other words, did you solve the user’s problem in the best way possible.

On-page SEO also includes optimizing page elements such as meta descriptions, title tags, headings, and image alt tags.

Off-Page SEO 

Website authority plays a big role in organic search rankings. Generally, domains with more high authority backlinks perform better in organic search. In fact, backlinks are one of the top three ranking factors.

A well crafted off-page SEO program leverages PR, social media, influencer collaborations, bylines, and standard outreach to build relevant backlinks. These links pass along authority to specific URLs they link to, as well as the entire domain.

Technical SEO

Technical SEO involves the optimization of the technical components of a website. This typically includes CMS, coding, scripts, page load time and site speed, URL structure, XML sitemaps, robots.txt, schema (structured data), and more. As a result, search engine crawlers can discover, navigate, and index the right pages.

Additionally, technical SEO ensures that web pages adhere to Google’s Core Web Vitals metrics to offer the best user experience.

Content marketing

A high-quality, comprehensive content strategy is vital to SEO. But what does it mean?

Essentially it means everything you publish is expertly-written, authoritative, and trustworthy. Google refers to this with the acronym E-A-T.

Simply put, a well-researched keyword strategy along with high-quality content that aligns with user intent helps your website rank higher.

Adding original visuals like videos, images, screenshots, memes, and infographics can also influence your SEO success. That’s because these elements reach a broader audience and support link building tactics.

What is search engine marketing (SEM)?

Search engine marketing (SEM) is the use of paid search platforms to gain visibility in the search results and bring more targeted traffic to a website.

SEM requires purchasing pay-per-click (PPC) ads from Google Ads, Microsoft Ads (Bing ads), Yahoo, or other search engine advertising programs to have your brand appear in the search results.

Using paid ads involves the ability to set a budget, capitalize on multiple ad types, run cost-efficient ad campaigns, create enticing ad copy, and analyze data to determine the value and success of the ads. It also involves the ability to optimize campaign and ad performance by adjusting the various levers of a campaign on an ongoing basis.

SEO vs SEM differences

The main difference between SEO vs SEM is that SEM directly purchases search visibility while SEO earns it. So, SEM competes on budgets and SEO competes on quality and relevance.

Here are some more differences between SEO vs SEM.

Cost of SEO vs SEM

It’s important to note that both SEO and SEM have implementation costs which affect ROI. SEO costs more money to implement given the number of folks involved, and it takes longer to achieve results. However, it ultimately yields a much higher ROI due to its compounding returns.

Conversely, SEM has a quick ramp up period, requires a lower lift, and generates revenue more quickly. So, if you compare costs on a short-term basis, SEM will win. But if you stretch the scale out to 24 months, SEO comes out way ahead.

Here’s an example.

If you have an in-house SEO team, there are costs for salaries, benefits, equipment, training, management, and an SEO technology stack. If you work with an SEO agency instead, you’ll pay a monthly fee and have a much quicker ramp up period to production.

With PPC ads, you often have lower costs for an in-house team or agency. However, you have the additional cost per click (CPC) of the ads. And these costs can be in the millions of dollars per month depending on your market and budget and the type of agency you work with.

Often, companies pay exponentially more for ad clicks over SEO monthly costs, even though SEO can lead to cost efficiencies and greater business performance. For a deeper dive on this topic, read our post about the upside-down approach that many brands take to SEO vs SEM budgets.

SEO vs PPC: Which One Has Better ROI?

Read the Article

Time it takes to get results

Time is a major consideration when comparing SEO vs SEM. You can generate traffic from SEM efforts almost immediately. In contrast, SEO can take months to deliver meaningful traffic gains.

Given the difference, it’s vital to be strategic with how you prioritize your approach. If you need to quickly drive traffic to a temporary web page for a seasonal event, SEM is your best bet. However, if you want to launch an evergreen content hub around a high value keyword that will drive compounding value for years? You need SEO.

Long-term, compounding value

SEO has a big advantage here. In fact, it’s really the only choice. With the right strategy, your web pages can remain at the top of the search results for years, continuing to generate revenue with minimal investment.

In that way, SEO is like a fusion reactor. Once it reaches ignition, it keeps producing efficient results.

Jonas Sickler


That’s because most of your costs are front-loaded for SEO. It takes a big initial investment to create a piece of content and build links. But when that page ranks in the top 3 positions, its ranking position becomes self-sustaining. Organic traffic turns into backlinks, which maintains or improves your rank, which yields more backlinks, and so on.

And as you improve your SEO, your organic search results compound over time, with a rising tide lifting all boats. In other words, as the overall domain gains authority, individual web pages also benefit. To that end, SEO is the only marketing investment that accrues value over time.

Alternatively, SEM only offers single, transactional gains. Once the ad campaign stops, so do the traffic and leads. Literally, they go to zero as soon as you end the campaign.

Testing opportunities

Once you start an SEO program and optimize your web pages, it can take months to see the impact and ascertain if your keyword and content strategies are working. In this way, testing and insights take time.

In contrast, SEM is a good marketing vehicle for fast-paced testing and insights gathering. With SEM you can test keywords, ad copy, and bidding strategies at a far faster pace than with SEO. This also creates opportunities to improve landing pages based on real data in a much shorter time frame.

SERP real estate

SEO offers the opportunity for a brand to capture more real estate in the SERPs. This can include featured snippets, knowledge graphs, map listings, People Also Ask links, image or video carousels, interesting finds, and more. By utilizing multiple digital assets, you can occupy several listings in the search results.

Alternatively, SEM offers only an ad position, extensions, and sitelinks.

In other words, with SEO, you can dominate the page. With SEM, you can gain slightly more real estate within one ad space on the page.

Click-through rate (CTR) of SEO vs SEM

SEO results in higher CTRs than paid ads do. In a study done by WordStream the average CTR in Google Ads in all industries is just 3.17% for search. Meanwhile, a study from Sistrix shows that a #1 organic position in Google can result in a CTR of 34.2%. According to organic CTR tracking by Advanced Web Ranking, a #3 organic position in Google often translates into a CTR between 8% and 10%.

Trustworthiness of SEO vs SEM

When it comes to trust, it’s not even close. Searchers overwhelmingly trust organic search because they know those positions are earned rather than purchased. And as Google has prioritized signals that determine user experience and content quality, the trust gap has only widened between SEO vs SEM.

SEO vs SEM similarities

A major similarity between SEO and SEM is that they both target keywords to drive traffic to a website. Although the process used to attract that traffic is very different, they both rely on targeted traffic that can convert into leads and sales.

There are a few other similarities between SEO and SEM, as outlined below.

Brand awareness

SEO and SEM are both effective at building brand awareness. Being more prominent in the organic search results and occupying paid ad positions allows you to increase exposure that can help improve brand perception, credibility, and trust.

(However, a major difference is that SEM is often not a viable option at the top of the marketing funnel due to cost. SEM is commonly used instead in the middle and bottom of the funnel.)

Increasing website traffic

Both SEO and SEM offer the opportunity for a brand to increase targeted website traffic. Organic and paid listings in each digital marketing channel sends users to your website. If you couple effective title tags and meta description text (SEO) or effective ad copy (SEM) with compelling content that targets their search intent, you’ll have a winning formula for traffic growth.

SEO vs SEM: Which is better for your brand?

When does it make sense to invest 100% of your efforts into SEO vs SEM, and when should you combine SEO and SEM?

There is no one-size-fits-all answer to these questions. Instead, there are a few factors that can determine which is the better option, such as budget, goals, business growth stage, and what your competitors are doing.

When to use SEO

Many brands use SEO as a core part of their marketing plans. The long-term value of SEO can range from stronger brand awareness to an increase in traffic, lead generation, revenue, and online market share

But when should you focus only on SEO? Below are some factors that can help you decide.

You have time

SEO is not a marketing strategy that will bring results immediately. In many cases it can take many months to begin to bring in organic traffic that can generate leads and sales. But if you’re creating an evergreen content hub, then you have time on your side.

You’re looking to solidify your online reputation

SEO can be used to control the message in your branded search results. This extends far beyond the use of your own website, and can include the use of microsites, other owned digital assets, social media, press releases, and news coverage. The broader control of your brand SERPs is an important step in online reputation management.

Long-term investment

If you are looking to make an investment in your brand for the long-term, then SEO is a highly effective strategy. SEO efforts can have long lasting effects for brand- and business-building. Once a website is high ranking, its pages can remain at the top of the search results for a long time, assuming you’re maintaining your website properly. 

When to use SEM

SEM offers the opportunity to ensure that a brand will be seen in the search results quickly. In the SERPs, advertisements appear either at the top of the page or the bottom of the page. The top-of-page ads are beneficial as searchers see the ads prior to viewing any organic results. The bottom-of-page placements can also be helpful, in that they are the final option that a searcher who scrolls down the page sees.

Below are a few times when it can be beneficial to focus on SEM alone.

Immediate results are needed

Because PPC can bring immediate results, it is perfect for new brands or brands that are just starting their SEO efforts. Within a short time you can have your budget set, ads created, and visibility when a search is conducted.

Test keyword effectiveness

If you are interested in starting a SEO campaign or other marketing campaign, but want to determine the keywords and ad messaging that are most successful, an SEM campaign can help. Doing in-depth keyword research and testing with a paid ad campaign can determine which keywords, messaging, time-of-day, and other marketing levers are the most beneficial for generating traffic and customers that convert.

When to combine SEO and SEM

Many successful brands integrate SEO and SEM strategies because they each offer complementary benefits.

Of course, running both side by side will require an investment in both time and money. It is important to consider both aspects before diving into a combined search marketing campaign.

Below are some benefits of including both SEO and SEM in your digital marketing strategy.

Dominate the SERPs

Imagine ranking on the first page in a search engine and also having ad placements. This is called dominating the SERPs and can be extremely effective in ensuring your brand is highly visible against the competition.

However, bear in mind that some of your paid listings could cannibalize your organic clicks, costing you more money than necessary. So, always audit your paid keywords to ensure that you aren’t overspending.

Implement remarketing campaigns

Okay, so retargeting is more about SEO vs PPC than SEM because the ads don’t appear in the search results. However, it’s a related initiative that supports a holistic marketing strategy, so it’s worth mentioning.

Although your SEO efforts may be earning you a lot of targeted traffic, that traffic might not immediately convert. This is where retargeting comes in.

By targeting those visitors who didn’t convert with paid ads on platforms like LinkedIn or Facebook, you can actively bring them back to your website and take that next step.

Improve SEO efforts with SEM data

PPC ads can also provide important insights about search queries to support your SEO strategy. By testing various PPC campaigns in Google AdWords with specific keywords you can see which search ads perform the best in terms of user clicks and conversion rates. Then, you can apply what you learned from the paid results to your organic SEO efforts.


What is the main difference between SEO and SEM?

The main difference between SEO vs SEM is that SEM purchases organic search visibility while SEO earns it. So, SEM competes on budgets and SEO competes on quality and relevance.

Which is better: SEO or SEM?

There are a few factors that can determine which is the better option for your brand, such as budget, goals, business growth stage, and what your competitors are doing. Ultimately, a combined approach that balances short-term gains with long-term growth is ideal.