Differences between SEO and SEM

Within search marketing, there are significant differences between the strategies of organic positioning (SEO) and the management of sponsored links in search engines, which is known as SEM (Seach Engine Marketing).

Table of contents [hide]

What is SEM?
What is SEO?
How can SEO and SEM search results be differentiated?
What is the main difference between SEO and SEM?
SEO vs SEM, Metrics to consider
    Number of keywords
    Flexibility of the strategy to changes
    Changes in the rankings
What strategy to choose, SEO or SEM?

Often, these two concepts are confused by users, although in practice SEO and SEM affect different areas within search engine results pages. What is SEM?

The concept of SEM (Seach Engine Marketing) refers to the promotion of a website in search engines through the use of paid ads through platforms such as Google AdWords or Bing Ads. And sometimes, this concept is extended to refer also to another type of advertising through these and other display platforms and social media, where it is usually paid based on the clicks generated by the ads. Through this strategy, the objective is to give immediate visibility to our website, since since we configured the campaigns and bid to leave, our ads have the possibility to appear.

What is SEO?

The concept of SEO (Search Engine Optimization) refers to the work of optimizing and increasing the popularity of a website, with the aim that the site is traceable by search engines, correctly indexed and relevant enough for some or Many of the pages are displayed in the top positions of search engines for certain search queries of users.

Therefore, it is about getting to appear in the first results (the ideal is on the first page, and if possible, in the first five positions) of a search engine for a set of searches that interest us, but without having to pay a direct advertising cost for each visit, thanks to which we are very relevant and / or popular. And is that to respond to a search, different search engines evaluate dozens or even hundreds of signals from all websites, to determine which are the best response to that search, with the aim of users have the best experience possible and find what they are looking for quickly and easily.

A website optimized for SEO is more likely to be positioned in the top positions of organic results. Within SEO positioning work there are 2 large sets of factors that we can optimize:


It includes all those actions that we carry out within our own website to optimize it for the search engines. For example, have friendly URLs, reduce loading time, give original and relevant content, provide the user with security and a good browsing experience ... SEO OFF-PAGE

It encompasses all those optimization actions that are used to increase the popularity of our website. This is achieved mainly by making other sites link to us (each site that links us is giving us a vote of confidence, and also depending on the popularity of the site that links us, this link has more or less value). How is this achieved? For example, through the publication of guest articles in other blogs, giving us registration in relevant thematic directories, distributing content that is viralized by social media and third party sites, publishing press releases and, ultimately, being online references in our subject or sector ... These signals are external factors, since they do not imply the realization of technical changes in our web.

SEO and SEM, therefore, are two strategies or ways of working with search engine positioning, totally complementary, and in fact it is highly recommended in most cases to work both in a joint and coordinated manner.

    How can SEO and SEM search results be differentiated?

Very easy, in search engines, sponsored or paid ads are displayed under an "ad" tag, sponsored links or similar (for example, in the case of Google, Bing or Yahoo!). Usually these results come out in the upper area, but we can also see them sometimes in the lateral area and in the lower part of the page.

For organic SEO results there is no label and they are usually displayed immediately after the first sponsored links.

What is the main difference between SEO and SEM?

The main difference between SEO and SEM is that with an SEO strategy we do not have to assume a direct cost for each visit, as we do with the SEM strategy. However, as we will see, this does not mean that SEO is always cheaper to carry out or does not involve any cost.

 The combination of both SEO and SEM is especially attractive in order to obtain better results in the short, medium and long term.

SEO vs SEM, Metrics to consider

To establish the differences between SEO vs SEM, we will analyze the following aspects: Number of keywords

 SEO: limited number of keywords.
 SEM: unlimited number of keywords.

At least, in principle.

When we propose an SEO strategy, the number of keywords with which we can work is limited, since it depends on the amount of content and pages that our website has. The usual thing is to work on a keyword and its slight variations (singular and plural, with and without preposition, etc.) for each page. If we try to work each page for several keywords, we will find that in the end that page is not really relevant for any of them. This would be like trying to work different topics on a single page, when the ideal is to focus on one thing per page. It is better to talk a lot about something than to speak little about many things (at the level of a single page). Therefore, if our portal has few sections of content, we will not have too many options. On the contrary, if we are developing new sections and contents, we will expand our opportunities to be more relevant with our SEO. Unless we have an online store, a very good option is to incorporate a blog to our site.

In the case of paid advertising (SEM), as it is a bidding system, we can choose all the keywords for which we want to leave, paying, of course, if we receive clicks for them. This allows to identify those keywords that bring qualified traffic and that generate conversions. Therefore, it serves us both for prospection and for conversion. However, we must be careful, because if we bid on key words that are not very relevant, the search engines will detect it and make us pay an extra cost to go out, making it difficult for us to appear or show us less times. In addition, if we bid on very broad keywords, we run the risk of receiving a lot of low quality clicks, which will cost us a lot. These are the causes why for many searches nobody is announced.


SEO: we pay for the optimization work (professional in payroll, external or SEO agency).
SEM: you pay for visits (to Google, Bing, etc.) and for campaign management (payroll professional, external or SEM agency).

Defining an SEO strategy with short, medium and long term implications and executing it requires the work of one or more specialists who know this task perfectly. This includes personnel with technical knowledge at the web level to work on those aspects related to the technology of our website (upload speed, tag optimization and HTML code ...) and personnel specialized in the generation of content, that is, people who know how to write and communicate. In many occasions it is difficult to find a person who is able to work effectively both, so it may be interesting to have two different profiles (one more technical and one focused on writing and copy) or work with an agency that provides the service full. Otherwise, our SEO strategy may limp.

In the case of SEM, a professional is required to know how the main payment platforms work in search engines, especially Google AdWords. These platforms are increasingly complex when you know how they really work, but give us many facilities to mount a campaign in a few minutes, so it is extremely easy and quick to create a campaign that foolishly spends our money without getting results . Bearing in mind that each click that they make us will suppose an additional cost to the own professional, we must take it into account.

In any case, both for SEO and for SEM we must bear in mind that whoever executes it must be a well-trained professional in these areas, and better if he has experience. The online world is increasingly competitive and professionalized, so if others do better than us, either because they have more experience or greater budget and resources, they are more likely to position themselves better. Therefore, we will have to define our marketing objectives based on who we compete with, and be reasonable about what we can achieve with our resources. Weather

SEO: the results are obtained, above all, in the medium / long term.
SEM: the results are obtained almost immediately, and you can extend everything you want over time.

While there are times when we can get the first SEO results in a few days, the normal thing, especially when we have a project that begins with certo, is that the results take time to arrive. Sometimes, weeks and other months. The continuous and uninterrupted work that is being developed (there will always be things that we can improve or polish) is what will make our portal take off at any given moment. This is because the search engines want to make sure that our project is serious and long-term. Sometimes it happens that we have done an impeccable work of optimization and we do not obtain hardly visible results. And, suddenly, one day, our positioning shoots up, simply having continued with a continuous work but without having done any action that justifies this takeoff. And from then on, we must dedicate ourselves to maintain it and to continue improving it, because it can also be lost.

On the other hand, through the SEM strategy, we can appear in a matter of minutes in the first or second place of the search results, surpassing all SEO results in a single stroke. This will make us get results (visits and conversions) almost from the minute zero. However, a SEM campaign requires a lot of experimentation and analysis, especially at the beginning, what is known as campaign optimization. While you should expect results in the first month, until the second, third or fourth you usually do not get the best results. Therefore, it is good to have a little patience if we see that in the first month the sales do not yet amortize the cost of the campaign, as long as you see a work that progresses and solve the problems that we find ourselves. These problems sometimes do not depend on the campaign itself, but on the part of the conversion funnel that depends on the company itself (being able to close opportunities or leads, having a product or service that is really interesting, a price competive, ...) and the web. You have to see it also from the point of view that a new competitor enters the market, and the competition is going to move and make it difficult, sometimes even using unethical techniques or fraud with clicks.

And once our SEM campaign works, we should not see it as a strategy that replaces SEO, but as an additional and complementary strategy. While our campaign is profitable, we can use this type of advertising to generate conversions, visits or sales on a recurring and continuous basis. In our case, we still have campaigns that started in 2006 and 2007. In fact, for many businesses, the SEM strategy attracts the most conversions and is essential. However, there are also businesses in which the SEM strategy is difficult to monetize and is limited, with SEO prevailing. Flexibility of the strategy to changes

 SEO: it is not flexible to changes.
 SEM: it is very flexible to changes.

In SEO positioning, for changes to take effect, sometimes days or weeks go by. For example, for a title change to occur, it is necessary for the search engine robot to crawl the page again and update the result in its index on its servers. And we can not propose to change the titles every day.

In SEM any change in the campaign is applied immediately. For example, change the texts of the ads, pause a keyword that does not give us good results, add others, change what we bid to raise or lower our position ... CTR

SEO: several studies show that CTR (click rate) below the 5th position is less than 5%, which greatly conditions the optimization work. In fact, going out on the second page is practically like not being, as only 1% of users spend just one page. And leaving the first usually generates click rates close to 30%.
SEM: in the case of advertising systems such as AdWords, very high CTRs can be obtained in the first 4 results, which are those that come out in the TOP zone, reaching figures higher than 10% and up to 30% in the case to be in first position.

There are users who prefer to click on organic results (SEO) before paying results, because they know they are ads.

We leave you a study that talks about the CTR.

What can be done? ... There are ads that, as they have a commercial purpose, offer the user a content that is not what they are looking for. However, if the SEM campaign is designed properly, this should not happen to a large extent. If the search has a commercial intention, a share may be equal or more relevant than an SEO result, given the large information it may contain (Google has recently extended the extension of its ads).

In any case, both in SEO and in SEM, the CTR decreases with the position. The lower we are, the fewer clicks we will receive.


SEO: you should look for originality, extension, quality and relevance.
SEM: you should look, above all, for relevance, in addition to giving it a more commercial focus, focusing more on conversion.

In SEO, the contents of the pages that appear in the first organic search results are positioned by the relevance of the website within a specific topic or sector and by the quality of its contents. Therefore, it is more likely that the user can find the answer to what they are looking for in the organic search results.

For its part, the SEM strategy has a clear and obvious commercial purpose. That is why most of the time these contents do not meet the needs of users who perform search queries. If you work the SEM, it is highly advisable to have specific landing pages and very focused on giving the user what they are looking for and taking them to the conversion, using texts and claims that encourage action, and facilitating the user to reach the goal that we have raised with the campaign (registration, request, call, budget, download, sale ...). Visibility

SEO: there is no guarantee to appear in the first results.
SEM: from the moment the campaign starts it is possible it appears in the first results.

By working the SEO nobody can guarantee that you will appear on the first page of the organic search results or in a certain position at a certain time. Who says that, or is trying to deceive you, or is using unethical or fraudulent techniques, which in many cases can lead to serious penalties. There must be a job behind, that is clear, and it is normal for this work to achieve some results within a reasonable period of time (weeks) and gradually progress.

However, it must be assumed that the positioning may work for months or even years and the objective can not be achieved (positioning a page for a search in the TOP10) because the competitors have been there for a long time or have resources superior to US. In that case, you have to look for other types of solutions.

In SEM, if you optimize the campaign correctly you will appear on the first page almost instantaneously, and even in the first position. It's easy, as long as you invest in the campaign, you'll have visibility. And if you bid a lot, you can go first. However, in the long run, it is not just a question of pushing a lot, but of structuring the campaign and optimizing it correctly. With SEM it is possible to leave first and pay less than the second. Although in hyper-competitive environments, the logical thing is to get out better positioned as you bid. Changes in the rankings

SEO: there are no big fluctuations in terms of the position that is occupied in the ranking of results.
SEM: the dance of positions can be constant.

In SEO, as a general rule there is not a big dance of positions in the rankings, since there are hundreds of factors that are considered and it is difficult for a single signal to produce important changes. The big changes usually come when the algorithms of the search engines implement modifications that affect the weighting of some signals. This usually happens a few times each year. Therefore, if a website is very well positioned, it is difficult to overcome it in a short space of time.

One of the main positioning factors is the age of the domain, but also the freshness of the content. So on the one hand, the oldest websites have certain benefits. On the other hand, the most recent articles tend to have greater relevance than older ones.

In SEM, on the other hand, fluctuations with constants, since if any of the competitors modifies their bid or makes changes in the campaign or on the web, the ranking of the ads is modified, which depends on a mathematical formula that has Count the bid and a quality factor that is calculated in real time for each search. Measurement

SEO: increasingly difficult to measure.
SEM: easy to monitor.

If we use any web analytics tool such as Google Analytics, we will have realized that since Google is concerned about privacy in searches, identifying as 'Not provided' the keywords that users search on Google having a session started is more difficult know the queries or keywords for which we are getting traffic.

In order to measure the metrics related to SEO positioning we can use the tools for Webmasters offered by the search engines, in the case of Google, Search Console. This tool gives us some information about the positions and keywords that have generated us clicks, but the information is incomplete, making the work of any SEO difficult.

At SEM, thanks to the tools that advertising platforms such as Google AdWords provide, we can have all the data and statistics of keywords and metrics related to a campaign. Easily identify the keywords by which we get more visits and conversions etc. In addition, in Google Analytics we can also have this information completely.

The initial investment in AdWords can be really interesting to know which words are searched, which bring us traffic to our website and which are the best convert.

What strategy to choose, SEO or SEM?

If you want immediate visibility, SEM is the most recommended. You can appear in the TOP area of ​​the search results, surpassing the results of SEO. While, an organic SEO campaign could take weeks or months to reach the first page of Google.

In Idento, as an SEO and SEM Agency, we suggest you analyze your business (contact us without commitment) to see which one will be most effective, although in most situations the combination of both is what will give you short, medium and long term results. long term. SEO or SEM Which one to choose?

Within this mixed strategy, for SEO you can choose to start trying to position those keywords that for example have a higher CPC (Cost per Click) on platforms such as Google AdWords, as well as those with a local scope. So periodically you can analyze the results and see if those keywords have been positioned by SEO to stop bidding on them in AdWords. In this way, you will have visibility in search engines and apart you will be able to reduce direct costs progressively.