Differences Between SEO and SEM

Desk with marketing book and supplies

Search Engine Optimization (SEO) and search engine marketing (SEM) are vital parts of modern online marketing. However, while they may seem similar, they are actually different marketing strategies that require unique sets of resources and effort to achieve. While there is some minor overlap, the tactics diverge in many key ways. If you want to take full advantage of your online presence, it’s imperative to have a good understanding of SEO vs SEM and when to implement each strategy for optimal effect. In this article, we will outline the key differences between the two and how to properly use them.


A big component of diversion of SEO vs SEM is their cost. Generally, SEO is an unpaid strategy. You may pay for an agency to do SEO efforts for you, but it is something that can be achieved for free if you were to do it yourself. Meanwhile, SEM is a paid strategy. Rather than focusing on only organic traffic to your site through Google Rankings, SEM incorporates paid traffic through ads or sponsorship. Both are great ways to increase the number of visitors to your site. But while SEO is considered “organic” traffic, SEM is not.

General Definitions

Before delving deeper into SEO vs SEM, it’s important to know their specific definitions.


SEO is focused almost entirely on optimizing your website to show up higher in search engines like Google. The higher your ranking on Google, the more people will visit your site. The top Google search gets a third of all visits on its own. So, it’s incredibly important to have a higher ranking site and marks one of the key separations between SEO and SEM.

Google on smartphone


SEM prioritizes paid advertising strategies. The primary one is pay-per-click advertising, which essentially forces your site to the top of Google results with an ad sticker. It can also advertise your site across social media and encompasses a broader range of sponsored content. The difference between SEO and SEM is that SEM is more aggressive and doesn’t bring “natural” visitors to your site.


A significant separation between SEO vs SEM is in how long it takes to get results. SEO is a long-term strategy that shoots for lasting results by consistently ranking high on Google. As a result, you may not see benefits until three to six months after you start. SEM, on the other hand, generates instant results and more traffic as soon as your ads are live. However, SEM efforts see diminishing marginal returns. It will get you more customers now, but not necessarily long-term. When choosing between SEO and SEM, SEM gets you more customers now, but SEO pays off larger in the long run.

SEO Advantages

These are the key advantages of SEO vs SEM:


SEO shows your company to potential customers in an organic way through Google. Customers aren’t being directly advertised to, they specifically choose your site out of many other options. Advertising, while effective, often comes across as inauthentic to customers. With SEO, you avoid that.

No Ad Spending

We mentioned it before, but it’s worth mentioning again. SEO efforts require no spending to use properly. All you need to invest is time and effort to see benefits throughout the year.


When it comes to SEO vs SEM, SEO is always more reliable. In fact, 39% of purchase decisions are influenced by relevant Google searches. This is mainly because it generates traffic to your site constantly. Ads may only stay running for specific days or times, but your Google ranking will persist. That persistence is one of the key differences between SEO and SEM.

Person typing on laptop

SEO Flaws

It’s also worth noting the downsides of SEO in the debate between SEO and SEM.

Constant Maintenance

Unlike SEM, SEO isn’t a one-and-done task. You need consistent efforts to maintain your top spot in Google, especially as search practices change and competitors fight for your spot. Efforts for expanding and maintaining your strategy will be vital in considering SEO vs SEM.


SEO isn’t going to give you immediate satisfaction the way SEM will. You often need to wait at least a few months to see substantial increases. For organic, long-lasting results, the wait is worth it. But if your company needs to see results now, SEM may be the way to go.

SEM Advantages

Now that we’ve covered the pros and cons of SEO, let’s cover the pros and cons of SEM.

Immediate Impact

With SEM vs SEO, you don’t need to wait for your results. Your ads will immediately get more eyes and traffic to your site. Paid searches garner 15% of all trackable traffic through Google. You also get total control of who sees your ad, the impression it gives, target times, and a lot more.

Targeted Ads

Targeted ad on Google search

With control over where your ad shows up, you can target a specific audience. This is a key difference between SEO and SEM that you can use to your advantage. Targeted campaigns are much more effective than general campaigns since they can be perfectly crafted for your audience.

SEM Flaws

Now for SEM’s downsides in the SEO vs SEM fight.

Higher Spending

Price is the biggest diverging point for SEO and SEM. Running SEM campaigns costs money, not just for running ads but for developing them as well. Plus, your gains in traffic are inevitably tied to your ad spending. The second the ads stop, traffic slows down.

Diminishing Returns

Running SEM campaigns requires the constant output of resources and time to achieve consistent results, with the potential for traffic to decline at any moment. SEM will get you good benefits now, but may not outweigh the cost in the future.

Final Thoughts

Ultimately, it’s up to your preferences and circumstances to decide on SEO vs SEM. If you can handle a lower return on investment with the goal of persistent, valuable gains in the future, SEO is the way to go. If you need to see results now, target a specific group of people, and have the right budget, however, SEM is an excellent option. Either way, you’ll see benefits for your site. But their lasting value varies greatly.