SEO and SEM: What are they, differences and how they work?

Digital Marketing, SEM, SEO

SEO and SEM are really two sides of the same coin, but they consist of very different actions and relate to different aspects of marketing. Sometimes the two terms are used in the same context to refer to a similar set of activities, which can be confusing to those not so familiar with this world.

So,what is the difference between search engine optimization (SEO) and search engine marketing (SEM)? How do they relate and work together? Any digital marketer should be well aware of these two terms and understand their importance in this area.

Keep reading our article by Rodanet, an expert SEO and SEM agency, to discover the role that SEO and SEM play today in digital marketing.

What is SEO and SEM within search engines like Google?

Since search engines created new ways for information to reach people, they also created new unique marketing options for businesses to reach their customers:

  • Search Engine Marketing(SEM)
  • Search Engine Optimization(SEO).

Nowadays, both SEO and SEM are the basis of the operation of many businesses on the Internet, since any website that wants to gain notoriety and visits must base part of its efforts on one strategy or the other (or even both).

But, to understand how SEO and SEM can help your website, you must first know what they are and how they work.

seo and sem positioning

What is SEM?

Search Engine Marketing is essentially paid advertising on a specific search engine.

Take a Google search for “car rental” as an example and you’re sure to get maybe 3 or 4 results at the top that are labeled
Ads “

sem announcement
Payment results for “Car rental” (SEM)

These are ads from companies that pay to appear there, and they pay only if the user clicks on the ad.

In other words, the user or company pays the search engine to list their website above the top organic results every time someone searches for specific keywords (of their choice). You are only charged if the user clicks on the ad.

The advantage of SEM is that you gain more notoriety than sites that do not use it: you can appear in the first organic positions and also gain space in paid positions.

The disadvantage of SEM is that since it is a marketing campaign… you have to pay for it. And depending on which keywords you want to work with, the prices per click can be very high. This means that, for those websites that are just starting out and therefore do not have the money to pay for SEM, they either have to greatly reduce their visibility or they have to aim for another strategy that is complementary to SEM.

This is where search engine optimization comes into play.

Advantages of SEM

  • It is faster to achieve visibility: placing search engine advertising gives us the opportunity to see traffic faster.

  • High targeting capability: SEM has great targeting power, being able to specify filters for your ads based on the location, language and behavior of your target audience.

  • Easy to configureSEM campaign is simple to set up and the tools to do so are intuitive and easy to use (Google wants to help you spend your money effectively): just set up your ad under the keywords to choose from and your maximum daily budget based on cost per click.

Disadvantages of SEM

  • The fact that the website gets traffic quickly does not necessarily mean that all visitors will become customers.
  • It is necessary to have an idea of our target audience and an established plan, which goes hand in hand with intuitive design, the use of SEO tools and knowing how to read web analytics data.

In other words:

A website that only does SEM and does not pay attention to other aspects of the site will hardly convert visitors into customers.

In addition,

  • It requires investment to run an SEM campaign, because it only works as long as you can afford it.
  • If your competition bids higher than you, they will force you to bid higher in order to recover your visibility in the search engine.
  • When the money runs out, all visibility and visits are lost.

The most famous SEM nowadays: Google Ads

google ads logo

Google Ads is nothing more than Google’s service that offers access to paid advertisements that appear above the search results of your search engine.

It is the most recognized SEM system worldwide, and works through a system of auctions of the aforementioned keywords.

Basic operation of Google Ads

  1. In order to use Google Ads, research must be done on the most relevant and most used words by the public when people make a search related to our product or service.
  2. We then “bid” on those words based on the amount we want to spend per day and the price of each specific keyword.
  3. The combination of this bid along with the ” Quality Score assigned by Google Ads based on the proposed ad is whatdetermines which Google ads will appear in the search engine.
  4. Each time users click on an ad, Google receives a price for each click (known as the cost per click, or CPC).

To “win” Google Ads auctions and have your Google ad appear for the selected keywords, you will have to optimize your Quality Score and increase the bid amount. The higher the Quality Score and what you bid for the keywords, the better the positioning of your ad will be.

How “good” is your ad and the targeting you have done for your campaign? The Google Ads Quality Score

The Google Ads Quality Score measures, on a scale of 1 to 10, the overall user experience offered by your ads and landing pages when they search for the keywords you bid on.

It is a kind of “score” from Google to know if your ads are useful to someone searching for a keyword on which you have programmed a bid.

The Quality Score is affected by three factors:

  • Expected click-through rate (CTR): the probability that someone will click on your ad when Google publishes it for the specific keyword.

  • Ad relevance: the relevance of the Google keyword to your ad group. Does it make sense to show an ad for dog collars when we search for cat beds?

  • Landing pageexperience: that the information on the landing page corresponds to what the ad offers.

If you want to improve your Google Quality Score, take into account these three factors as a whole. Adjustments may need to be made to your keywords, your ads, your website, or all three at once. That’s why sometimes it’s best to entrust your campaigns to a specialized SEM agency.

What is SEO?

With the term SEO(Search engine optimization) we refer to everything related to the optimization of the web to make it attractive to search engine algorithms.

NetMarketShare says that, in 2017, Google grabbed more than 79% of global search traffic, while the other major search engines lagged behind at 7% or less each. Therefore, the main focus when we talk about search engines in the context of SEO is Google, but we still have to remember that others like Bing, Baidu and Yahoo are still in the race.

Internet Live Stats, meanwhile, reports that there are more than 163,188 searches per second on Google every day. (Note that this figure was taken at the time of writing; if you click on the link, you are likely to find a different figure, as data from this source is collected in real time). This is a great activity with which any company should compete and that is why it is essential to know the area of digital marketing that we call SEO.

Search engine optimization (SEO) refers to the process by which search engines “crawl” content to see how effective it will be in attracting traffic. Search engines evaluate a number of elements of a website (such as keywords, tags and links) and rank it according to its ability to attract organic traffic based on a number of factors.

Some of them are:

  • Quality content: producing high quality content sends a message to search engines that our website and business offers a legitimate product or service. Part of the way they evaluate you is through link building and keywords.
  • User experience: Is our website designed in a simple and intuitive way for users? Is it fast and easy to navigate? Can users achieve their end goals (e.g., make a purchase) with ease?
  • Link patterns: Are you linking to authority sites? Where do the inbound links come from?

SEO will not be as expensive in the long term as SEM, since once the website is established in the first search positions for its target keywords, it will be difficult to remove it from there.

Furthermore, in the case of small businesses that don’t want or need a large reach, they can even apply basic SEO strategies themselves, as long as those responsible for the business are minimally skilled with their web management.

This means that you could work SEO for a minimum of hours, but benefit from the results for months. This also leads us to another conclusion: SEO can be cheaper than SEM, and in general in the long term it is (the ROI of SEO at 12, 18 or 24 months is higher than that of SEM).

Anyone can learn the basics of SEO and incorporate it into their digital sales, marketing and content strategy. And when you learn how to do it right, you’re sure to get more traffic. But learning the ins and outs takes some time and technical know-how; for the most part, it’s always a good idea to consider hiring an expert SEO company if you want your website to actually generate conversions.

On page SEO

On page SEO represents the set of rules that you can apply to your website, e-commerce or blog to make it “search engine friendly”. We have a full article on SEO on page, but in summary it consists of:

  • Metadata optimization, which includes the title tag, meta description, titles (H1, H2, etc.), image descriptions, which must incorporate the target keyword;
  • Text of the page well written and optimized for the chosen keywords.
  • Simple, well-formatted URLs that also contain the main keywords.
  • Web site performance optimization (WPO).
  • Implementation of buttons to share the text on social networks.

Off-page SEO

Off-page SEO refers to the processes by which “votes” are obtained from other websites to increase the confidence of search engines in our site.

For beginners, this may seem somewhat unclear, but try to think of it as a ranking system in which the site with the most “votes” is also the one with the highest ranking. The “votes”, in this case, are the links that come from other websites and that point to your web page (

To avoid any misunderstandings, it’s not just about how many links lead to your site, but also which sites those links come from. A big part of SEO is creating valuable, high-quality content (e.g., blog articles and website copy) that your target audience will find useful. Over time, this will drive more organic traffic to your website, more inbound link opportunities and, most importantly, more conversions.

Be sure to pay attention to these on-page and off-page tactics to ensure that your landing pages, web copy and blog posts are optimized for search.

These are the most commonly used techniques in off page SEO:

  • Linkbuilding
    Linkbuilding: to attract and obtain quality inbound links (so called“backlinks“).

  • Social signal
    to increase website traffic by sharing content through social networks;
  • Attract the attention of bookmarking sites such as Reddit, Digg and Stumbleupon.

Advantages of SEO

  • More visibility in the long term: one of the advantages of SEO is that it is a long-term web marketing strategy. From a good web positioning and the correct maintenance of the page, we can maintain the first positions in the search engines for months, even years.

  • Improve performance: SEO is much more than just traffic. Working to improve SEO involves optimizing all elements within the website. Improves performance, loading speed, web usability… which translates into a more efficient, fast, easy to use website, and therefore increase sales and conversions.

  • Create good content: Google is usually picky about the content it displays on its first page. For this reason, SEO forces us to learn how to create content that both users and search engines like, that is original and professional, and that makes use of the main keywords in relevant places, such as in titles, metatags, the first paragraphs of the web and in images.

Disadvantages of SEO

  • Going down the SEO road can be a long and difficult journey, with little guarantee of ranking in the top search results if you don’t work hard and/or have patience.
  • Certain knowledge is needed to develop the work, and a constant monitoring of both our website and the competition.
  • In addition, Google’s search algorithm is constantly changing (there are about 3 or 4 major updates every year), and in Google SEO you either adapt to those changes, or you die on page 7 of the search engine.
  • It is necessary to know and manage the main web analytics monitoring tools, such as Google Analytics, to know how to interpret the data they provide us and detect market opportunities that we can take advantage of for our website.

The most universal SEO measurement tools: Google Analytics and Google Search Console

To analyze if the organic traffic coming to your website is the right one, and to know where and how it comes from, it is necessary to know how to analyze the information provided by Google Analytics and to optimize/modify your website according to those needs. but how do I do it?

  1. Track the demographics and interests of your visitors. Google Analytics lets you know the age, gender, location and interests of your website visitors. Collecting this data allows you to know your visitors better so that you can offer them content or create products that meet their needs.
    For example, if you have an e-commerce store, you may want to identify the customer profile with the highest conversion rate in your store.
  2. Track your organic keywords. Google Search Console is Google’s free service that allows you to monitor and maintain your site’s presence in Google search results.
    • You can connect your Google Analytics account with Google Search Console and see your website’s top-ranked organic keywords. Together with other SEO tools, you can make better and more extensive use of these keywords on your page.
  3. Know your main referral sites. A referral is nothing more than another web page that links to your site, which means that through them you receive traffic and audience.

So… how does SEO differ from SEM?

SEO analyzes and corrects technical, usability and design problems that a website may have, as well as the online relevance of the site (known as backlinks, what other websites say about us).

This makes the site easier for search engines to “understand” and at the same time attractive to them.

Result: the website appears higher in search engine results pages.

The SEM what it does is to promote the web sites within the search engines without paying attention to correcting possible design or content errors or making use of natural positioning as SEO, but the results appear in one place or another according to the promotion system used (ads normal, display campaigns…), according to the budget available, and according to the segmentation chosen (geographic area, language, device…).

Since websites need users to access them for information, SEO and SEM are sister concepts that were destined to eventually appear and coexist as a natural consequence of market demand and needs.

So which is better? SEO or SEM?

Neither strategy is better than the other, because if one of them were weaker, it would have disappeared or become very residual. Both SEO and SEM are very much alive, and in fact, 90% of Google’s search engine revenue is based on what companies spend on SEM to improve their digital marketing. However, there are times when what you really need is a SEO and SEM professional to take your digital marketing to the next level.

SEO and SEM in Rodanet

Have you already learned all about SEO and SEM? No? Don’t worry. It is complicated. That’s why we have answers. The differences between SEO and SEM are quite marked, so it is important that we know how to differentiate them and get the best out of each one. In our Rodanet blog you will find more information and if you have any questions or comments please do not hesitate to contact us.

Copy & Content Strategist en Rodanet | | + posts

Tamara es redactora #seo y la boxeadora de la oficina. 🥊
Siempre escribe textos con gancho 😉

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