SEO vs SEM: What's The Difference?

Published: December 22, 2023 • Author: Ramal Ibrahimov



Contrary to popular belief, SEO and SEM aren’t the same thing. SEO is a digital marketing channel for boosting website traffic that can be combined with PPC, both of which are parts of SEM. The confusion often stems from their interchangeable use of SEO and SEM. 


However, they represent different ways to get search traffic.


SEM is the combination of SEO and PPC . They both aim to increase your website traffic, just in different ways. To understand what is SEM, you need to get familiar with SEO and PPC first.



Google search consists of paid and organic results. SEO brings organic traffic, while PPC uses paid search ads.



In this guide, we will explain what makes SEO and SEM different.

Let’s get started.


What is SEO?

SEO (Search Engine Optimization) means changes done on and off a website to improve its search traffic. By ranking individual pages of a website on top positions on Google for popular keywords, SEO allows to put your product or service in front of your target audience.

SEO consists of three major aspects:

1. On-page SEO means the changes done directly on a webpage for Google to understand its topic. This is the part of SEO where you optimize a webpage for certain keywords. The way it works is Google crawls your webpage, understands what it is about, and decides for which keyword your webpage has to be suggested in results. Examples of on-page SEO are meta tag optimization, content writing, and heading structure optimization.

2. Off-page SEO means the changes done beyond a website to increase its authority and trust in the eyes of Google. This primarily means link building – creating hyperlinks from other websites pointing to a specific page on your website. Such links are called backlinks. The more authoritative is the website linking to you, the better it is going to influence your rankings. Backlinks act as votes – if a website that Google already sees as an authority has voted for your site, your authority in the eyes of Google will increase.

3. Technical SEO means ensuring seamless access to your site and content by search engines and visitors. Before Google ranks your content, it has to crawl (discover) and index it (add it to their database). And one of the main purposes of technical SEO is to make sure your website is crawlable and indexable. This is done through handling errors, creating a sitemap, and creating schema markups. Other than that, technical SEO is focused on improving user experience signals like page speed.


Source: Ahrefs

What is PPC?

PPC stands for Pay-Per-Click and means advertising a webpage on Google where you pay each time searchers click on your ad. Besides keywords, you can target users based on their location and demographics.



The amount you pay to advertise varies for every keyword and depends on the competition. You can choose the maximum amount you are willing to pay for one click. Your ad rank – the position of your ad among all sponsored results – depends on your bid amount and quality score. If your ad click-through rate (CTR) is higher than that of competitors, your ad will move up to the first position and your cost per click will decrease. Therefore, it is important to write a catchy title and description for your ad.


What is SEM?

SEM stands for Search Engine Marketing and means increasing your website traffic through search engines like Google. SEO and PPC are two ways to market your business on Google. In other words, SEO plus PPC is SEM.

Differences between SEO and SEM

While SEO is a part of SEM rather than an alternative, we will compare SEO alone with the combination of SEO and PPC. Both SEO and PPC have pros and cons, and some businesses should go with both digital marketing channels. Here are the main differences between SEO and SEM:


SEM pays for each click.


In PPC, you will continue receiving search traffic only until you stop paying. SEO, however, is technically free. Once your webpage starts ranking high, it is a passive and free source of traffic.


SEO receives most clicks.


Just like in any other digital marketing channel, most Google searchers ignore ads and consume organic content. The top-ranking sponsored result on Google receives only around 8% of all clicks. Therefore, even if your PPC campaign is crushing the competition, you are still leaving a lot of money on the table. The most clicks from a search go to the top 5 ranking results or the local pack.


•  SEO takes much longer


SEO takes anywhere from 4 to 12 months to show noticeable results. Depending on the competition, some big companies run SEO campaigns that last over 2 years. This happens due to two main reasons:

1. Google needs time to trust new websites.

2. Building up your authority and catching up with competition takes time.

With PPC, on the other hand, you can start receiving traffic almost immediately. Time is definitely the main factor when choosing between SEO and PPC.


SEO is cheaper long term


While PPC provides almost instant web traffic and SEO can take months to start working, over the long term, the SEO expenses decrease and SEO starts bringing more and more profits. Therefore, if you run both SEO and PPC (SEM) campaigns for the same webpage, over time, SEO is just going to be much more cost-effective.

PPC is a better short-term solution while SEO is a better long-term strategy. If you need profits soon, PPC is a much more realistic way to achieve that. However, after a long enough time period, PPC becomes much more expensive than SEO.

This is where SEM comes in. For many businesses, the best strategy is to set up a PPC campaign and start receiving web traffic while simultaneously running an SEO campaign, and continue combining both until their SEO takes off. Some businesses might have to stop their PPC campaign once their organic traffic catches up.



For most businesses wanting to market through Google, going with SEM, that is, combining SEO and PPC can be the best decision. PPC starts bringing search traffic very soon, but SEO is cheaper in the long term. In addition to that, PPC gets only a fraction of the clicks that go to organic SEO results.