The Beginner’s Guide to Search Engine Marketing

FYI: This article was initially published on the Ahrefs Blog. However, it has been subsequently rewritten, and I decided to share the original version here.

What is search engine marketing?

Search engine marketing (SEM) is a type of digital marketing that utilizes search engines to drive more traffic to your website.

Many industry “experts” often use SEM to talk about pay-per-click (PPC) advertising. However, SEM encompasses both paid marketing and organic search engine optimization (SEO).

Let’s clarify this a bit.


The main difference between SEM and SEO is that the goal of SEO is strictly to get organic traffic from search engines like Google, whereas the goal of SEM is to use both organic and paid methods.

So SEO is a part of SEM.


The main difference between SEM and PPC advertising is that PPC is strictly about purchasing ad placements on a search engine, whereas SEM can include SEO.

We believe it’s best to have an all-encompassing SEM strategy that includes PPC ads and SEO so that you’re not leaving money on the table.

But how do you do that?

Three steps to building an SEM strategy

Building a cohesive SEM strategy involves determining which keywords to target with SEO, PPC, or both. Which strategy you use depends on a few things, which we’ll cover shortly.

So if you haven’t done keyword research already, that’s your first step.

You can learn how to do that from Ahrefs’ comprehensive keyword research guide. But if you want a quick way to find keywords, enter a few broad topics into a keyword research tool like Ahrefs’ Keywords Explorer and check the Matching terms report.

For example, if you have a site about fashion, you may enter broad topics like “fashion,” “hoodies,” and “tshirts.”
Keyword suggestions report

Then you can sift through the ideas for anything with decent search volume and reasonable keyword difficulty.

Once you’ve got some keywords, follow the decision tree below to decide whether to target them with SEO, PPC, or both:

Choosing between SEO and PPC

Let’s go through this process in more detail.

  1. Are searchers looking to learn or buy?
  2. Can you realistically rank anytime soon?
  3. Are the ads getting lots of clicks?

Question 1. Are searchers looking to learn or buy?

For this question, you’re analyzing a keyword’s search intent. You’re looking for one of two types of searches:

  • Informational
  • Transactional

To determine which type of search a keyword is, analyze the SERP for informational vs. commercial intent. In other words, are people looking to learn something or buy something?

For example, let’s look at the keyword “fashionable sneakers.”

The SERP overview shows us that most results are listicles with sneaker recommendations.

SERP overview in Keywords Explorer

SERP overview for the US from Ahrefs’ Keywords Explorer

This tells us this keyword is primarily informational. Searchers are looking to learn.

In this case, your questioning ends here in the decision tree because you know you should target the keyword with SEO.

However, if we look at the SERP for “hoodies,” all of the results are e-commerce pages selling hoodies:

SERP overview in Keywords Explorer 2

SERP overview for the US from Ahrefs’ Keywords Explorer

This tells me this keyword is transactional. So searchers are looking to buy.

In this case, we need to ask more questions to figure out how to target the keyword.

Question 2. Can you realistically rank anytime soon?
This is a question of keyword ranking difficulty.

If you can potentially rank organically for a keyword easily, you may want to consider SEO. If not, you will need PPC (at least in the short to medium term).

You can get a rough idea of how hard it may be to rank for a keyword with the Keyword Difficulty (KD) metric in Keywords Explorer. This metric runs on a scale from 0 to 100, with keywords scoring “0” being the easiest to rank for.

For example, if we plug the keyword “t-shirts” into Keywords Explorer, we see that its KD score is 74:

Keyword difficulty in Ahrefs Keywords Explorer

That signals that this keyword is likely tough to rank for.

We base our KD score on the number of referring domains (linking websites) to the top-ranking pages. If you scroll down to the SERP overview, you’ll see why KD is so high for this keyword—all of the top-ranking pages have hundreds of referring domains.

Referring Domains of the search results

However, KD only gives you the rough difficulty of ranking for a keyword. And it can sometimes be misleading. You need to analyze SERPs manually.

The point here is that you shouldn’t rely entirely on third-party metrics like KD when deciding the actual ranking difficulty of a keyword.

If you don’t think you can rank anytime soon for your keyword, use PPC.

If you think ranking in the short to medium term is possible, use SEO.

However, even if you can rank, you may still want to consider using PPC. To decide if this is right for you, you need to answer one more question.

Question 3. Are the ads getting lots of clicks?

Even if you’re able to rank for a keyword easily, high clicks going to ads signal that you may want to do both PPC and SEO to monopolize the SERP and get more clicks.

You can see how many clicks the keyword ads are getting in Ahrefs’ Keywords Explorer by hovering over the green, yellow, and orange bar in the Volume box.

Distribution of clicks on the search results

For this keyword, the paid ads get 12% of the clicks, and 4% of searches get clicks on both the paid and organic results. So roughly 15% of searches have at least one ad click.

This seems low. However, notice that 50% of searches result in no clicks whatsoever. This means that roughly 30% of searchers click on ads.

So, in this case, using PPC ads and SEO (if you can rank) is probably the best bet.

Rinse and repeat this process for all of your keywords to determine which strategy to use for each.

SEO and PPC basics

Now you should have a spreadsheet full of keywords, and you should know which ones you’re targeting with SEO, PPC, or both strategies.

Rather than overwhelming you with everything you need to know about SEO and PPC, I’ll offer the basics of how each of these works and give you links to dive deeper into the concepts.

Basics of SEO

For your SEO keywords, you’ll need to start an SEO campaign.

This means creating new content for the keywords you don’t have content for yet and optimizing old content for those you do have content for.

Essentially, SEO can be boiled down to three main activities:

  • On-page SEO (optimizing your content)
  • Link building (getting backlinks from other websites)
  • Technical SEO (optimizing your website’s code and structure)

Basics of search engine PPC marketing

For your PPC keywords, you’ll need to know the basics of how Google ads work.

Running an ad boils down to:

  • Choosing your ad type and goals for each keyword.
  • Having strong ad copywriting.
  • Picking the most relevant keyword themes.
  • Deciding on a budget.
  • Understanding the Google Ad auction.

First, create a free Google Ads account and familiarize yourself with the dashboard.

Then, watch this excellent video overview of how to get started with Google Ads.

How the Google Ad auction works

Google uses the ad auction system to determine which ads should be displayed every time a search is done or every time a site with Google Ads is visited.

This is important to understand because it can make the difference between running successful ads and wasting money on ads that are too expensive.

There are three main factors that the ad auction uses to determine which ads get shown on a page:

  1. Your bid – You can set the maximum bid amount you’re willing to spend per click. A higher bid amount means a higher chance of your ad being seen. But bid too high, and you may be losing money—so test this often.
  2. The quality of your ads – Google Ads uses a Quality Score to determine how relevant and useful your ad is to a search or webpage. The higher your score is on a scale of 1-10, the more likely your ad will be shown. So try to make your ad as high-quality and relevant to the target keyword(s) as possible.
  3. The expected impact from your ad extensions and other ad formats – This is additional information you can add to your ad, such as your company’s phone number or links to specific pages on your site. Google estimates how these added extensions will impact your ad’s performance and uses that estimate to determine how often your ad is displayed.

The main takeaway here is that two-thirds of the factors that determine how well your ad performs are specifically performance metrics, not just how much you’re willing to spend.

In other words: If you have a high-quality, relevant ad, you can earn more for less.

Search engine marketing examples

Now that you understand what SEM is and how to do it, let’s look at a few examples of companies that have used the full scope of SEM to grow their business.

1. Ahrefs

As I mentioned before, Ahrefs gets nearly 1 million organic visits to its site per month.

The estimated organic search traffic for is nearly 3 million visits per month

Organic search traffic estimation by Ahrefs Site Explorer

Our blog and landing pages have content that ranks for almost every SEO-related keyword you can think of.

Here’s the list of our best pages: top pages

The “Top pages” report in Ahrefs Site Explorer

2. Canva

Next up, we have Canva, one of the best graphic design tools. Ahrefs estimates its organic search traffic as a whopping 152 million organic visits per month!

Estimated organic search traffic for

Canva is an excellent site to explore because it employs SEO for numerous commercial and informational keywords. In fact, two of its most prominent keywords are “resume templates” and “meme generator.” These keywords are highly relevant to their offerings.

Despite the huge amount of organic search traffic, they are actively using Google Search Ads too.

Paid keywords for

“Paid keywords” report in Ahrefs Site Explorer

3. Statista

Statista provides a huge variety of statistics data from over 22,500 sources on over 60,000 topics receiving almost 6 million visits from organic search.

Organic search traffic for

Statistical data is one of the few things that people eagerly link to, and Statista’s pages receive links from tens of thousands of websites. This, in turn, further enhances their organic search rankings.

Best pages by links

“Best pages by links” report in Ahrefs’ Site Explorer

Final thoughts

SEM is crucial for almost all businesses these days. If you have customers who use Google, you should probably be implementing some form of SEM.

Hopefully, you now have a complete SEM strategy to execute.

Tim Soulo is the Chief Marketing Officer and Product Advisor at Ahrefs, a leading tool trusted by hundreds of thousands of SEOs and marketers worldwide. His SEO-related data research studies have been cited by media giants, including Inc, TechCrunch, and VentureBeat. He's also a regular speaker at some of the largest industry conferences around the globe, such as PubCon (US), BrightonSEO (UK), and the Digital Marketers Australia Conference (AU).