SEM and SEO - What's the Difference?

For people outside the search engine marketing industry, the field can be rather baffling. The reasons for this include -

• Overuse of acronyms
• People's inherent fear of computers and technology
• A lack of industry standards and no universally accepted definitions of terms
• Continual and rapid evolution of services and technologies

SEM (search engine marketing) and SEO (search engine optimization) are terms folks get confused about all the time. These terms can be defined any number of ways, but here's how I like to think of it.

SEM and SEO are both practices employed to increase a company's visiblity on the Web. Both use a variety of techniques to steer internet users toward particular Web pages.

SEM is geared toward human readers. SEO is geared toward search engine "readers".

When a human reader looks at a Web page, he will be influenced to act based on the design and content of a particular message. For SEM practitioners, the goal is to create the most persuasive design and content and then place it on a Web page where it will attract the most potential qualified readers. A well written, well designed pay per click ad, well positioned on the right Web page, leads to the greatest number of conversions.

SEO is concerned with how the search engine spiders are reading a Web page. A spider sees value in things such as internal links, inbound links from highly ranked Web pages, and keywords used in titles, subtitles, and anchor text. Various programming techniques can make a page difficult or easy for a spider to read. For SEO practitioners, the goal is to create Web pages that are optimally readable for specific keyword phrases by Google and other engines.

These definitions are overly broad and incomplete, but I think helpful nonetheless. Obviously SEM and SEO go hand in hand. Without having a keyword strategy, it's pretty hard to conduct effective SEM.  SEO takes time to produce results, whereas many SEM activities, such as affiliate advertising, can produce immediate results. A good a markerting program needs both - short term and long term programs to build a strong Web profile.