What is the Difference between SEO and SEM?

Search Engine Optimization vs. Search Engine Marketing

Many people use the terms “search engine optimization” (SEO) and “search engine marketing” (SEM) interchangeably, but nothing could be further from accurate! Search engine optimization is actually a part of search engine marketing—arguably the most important part.

When you optimize your site, you are taking measures to make it attractive to Google and other search engines. This involves making changes to your site itself, things like:

  • Optimizing the design and code of your site—Search engines have to be able to actually read your site in order to index it!
  • Double check that your site is W3C-valid and displays correctly in a variety of browsers—all the SEO and SEM in the world isn’t going to help you if visitors can’t actually see your site the way it is supposed to look.
  • Create search engine-friendly URLs
  • Selecting good keywords
  • Writing clear and appropriate meta descriptions
  • Using the right header tags
  • Selecting the ideal link text
  • Writing the best image alt text
  • Producing and optimizing quality content
  • Ensuring that the keywords you are targeting are the right ones
  • Creating a Sitemap
  • Ensuring your website is accessible — to both humans and search engines

Search engine marketing, on the other hand, involves going out and promoting your site—this is all done off your site. SEM involves things like:

  • First, before anything else! Optimize your site
  • Making appropriate use of resources like Google Webmaster Tools
  • Submitting your site to individual search engines and search engine services including Google Places if your site is geographically specific
  • Submitting your site to appropriate free directories that have a high Google PageRank
  • Paid advertising in directories and other sites—may include both static links or pay-per-click/exposure ads
  • Promoting your site in a search engine-friendly, honest manner
  • Maintaining an active and useful presence on appropriate and relevant comments and blogs, occasionally creating links to your site where appropriate in response to another member’s post. This is a tough one—it involves a lot of tact and good judgment. Also, this will not necessarily directly result in higher search engine placement as Google gives very little, if any, weight to these types of links. It may, however, result in actual real visitors coming to your site directly from these links.
  • If applicable to your site, writing appropriate articles for sites like About.com, eHow.com, and WonderHowTo.com, including links to your site.
  • If applicable to your site, creating useful videos and photo galleries and posting them on sites like YouTube and various photo gallery sites like Instagram.
  • Making appropriate use of Twitter, Facebook, Instagram, Pinterest, and other social media venues.
  • Evaluating your ROI and conversion rate and taking appropriate action based on the results—It doesn’t matter if a zillion people a day visit your site if you’re not seeing actual sales (or clicks, if you have an advertising-based revenue stream).
  • Going back to step one and maintaining the optimization of your site

Appropriate, ethical, and effective search engine marketing and optimization does NOT include:

  • Submitting your site to dozens or even hundreds of free-for-all link sites
  • Trying to get as many inbound links as possible, regardless of the source
  • Posting your URL all over blog comments and forums regardless of their content or relevance
  • Keyword stuffing
  • Using invisible text
  • Creating “doorway” pages for search engines only
  • Trying to “trick” Google or other search engines in any other way.