SEM And SEO Explained

Most of us have heard both of these terms used throughout many articles on internet marketing. But do you know the difference between the two? Take a look at the definition of both SEM and SEO and how the techniques, and results, differ.

SEM – Search Engine Marketing

SEM Search Engine MarketingAccording to Wikipedia, SEM is defined as “a form of internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion.”

While it can encompass a rather broad context, it is generally agreed that the single most defining factor of SEM is its use of unnatural, paid techniques to optimise a site.

Such techniques include paid directory listings, search engine advertising (banner ads, sponsored links, etc.), and pay per click campaigns.

There are many advantages to running an SEM campaign. Traffic that is paid for is somewhat predictable. It allows a business owner to forecast sales volume based on prior performance and budget for advertising expenses.

Search engine marketing reaches a large number of consumers, and they are usually part of a pre-qualified, targeted audience. The search engine company that you advertise with will offer their own form of promotion to boost your click through rate, and receive more revenue from you.

Increased inbound links and visitor traffic aids in reaching the top of SERPs. The design and content of advertising is nearly limitless, allowing the marketer to be creative and change material often. The conversion rates are usually higher.

Of course, running an SEM campaign can be quite costly, particularly if you are paying for click-throughs on the most popular keywords. Some consumers tend to shy away from companies that utilise certain techniques, such as sponsored listings, seeing them as spammers.

SEO – Search Engine Optimisation

Wikipedia defines SEO thusly: “the process of improving the volume or quality of traffic to a website from search engines via “natural” (“organic” or “algorithmic”) search results.”

In other words, a business can cater to search engines by performing tasks known to increase their rankings without paying for outright advertising.

SEO Search Engine OptimisationSearch engine optimisation includes such things as posting comments on blogs to create inbound links, listing complementary sites for external links, including meta tags on website pages, bookmarking content, and a host of other organic methods to increase position on SERPs.

Perhaps the greatest advantage to SEO is that it costs nothing but time. Consumers generally think of organic SEO more favourably, seeing it as an unbiased form of promotion. The result of increased organic traffic will be steady, and not affected by the duration of a paid campaign. Maintenance of a website that is already optimised is minimal.

Disadvantages include little control of SEO rankings and links. Marketers need to be careful to comply with the rules of search engine companies. Often it is hard to determine exactly what type of marketing to do, and how effective each technique truly is. Some business owners find it difficult to strike a balance between appealing to search engine bots and human visitors alike.

The bottom line is that there can be no truly effective SEM campaign without at least some basic SEO. SEM may reach more targeted prospective customers, but SEO is the practise that will ultimately drive traffic, rankings, and conversions for the long run.

About Sean Rasmussen

I am a passionate blogger and have been a full time internet marketer since 2005. When I'm not with my family, you will find me doing SEO, building websites for many of my clients, and creating products out of thin air! This is a cool gig and I love it!


  1. Thanks Sean for the very thorough explaination of the differences between SEM and SEO.
    I now have a good grasp of these concepts. I will continue with implementing the SEO strategies to optimize my sites. There is a lot of work ahead but I will take a steady approach and am sure it will bear fruit.

    I am still a way off attempting SEM strategies.

  2. Jazz Salinger says:

    Hi Sean,

    I’ve worked hard at understanding and implementing SEO strategies and I think I’m getting there. I’m still learning with SEM and I’m nearly ready to have a go. Especially since I may be able to find a free trial offer. You really make it look easy.

  3. Hi Sean

    Thank you for a well written article that clearly defines the concepts of SEM and SEO.

    While I see the benefits of using both, I still need to learn a lot about SEO as I don’t have volume or quality of traffic to my site yet.

    I want to learn as much as I can about search engine optimisation so that I can get my site ranking to no 1. This article and many other articles you have written on SEO are teaching me to do just that. Now I have to take massive action.

    Thank you.

  4. Jody Chambers says:

    Now I know! When you strart out in internet marketing all the terms like SEO, SEM, SERP just confuse the hell out of you….but bit by bit as you learn them term by term it all falls into place…and SEO and SEM are explained very clearly here. Thanks \m/

  5. That is a clear explanation of the difference between SEM and SEO. I particularly like the point that SEM works better with a foundation of SEO – and why woudln’t you optimise a site/[page anyway?

    At least with SEO money can come in with none leaking out as it can more disastrously with SEM

  6. Hi Sean,
    The benefits are there for SEM marketing as this article shows. I’m not ready yet to spend money on advertising so I will stick to organic SEO and learn about this form of attracting online traffic.

    I appreciate you pointing out the difference between SEM and SEO Sean. Now I will be able to distinguish when I hear the two options discussed.