"Search Engine Optimization (SEO) is the process of refining web content so that it is highly visible in Search Engine Result Pages (SERPs), when they are queried with specificaly targeted keywords." The Keyword Cracker

The goal of any search engine is to return content that is of a high quality, and valeu to the searcher. What kind of content is returned depends largely on the way that the query is constructed, with relation to the keywords used. The Traffic Acquisition blog identifies three such keyword types:

• Researcher's Keywords (used to define the niche)
• Shopper's Keywords (used to find products)
• Buyer's Keywords (used to find specific products to buy)

The key difference between Shopper's and Buyer's keywords is that Shoppers are looking for ideas, whereas Buyers are looking for products. The relationship between the three is generally accepted to be that the keyword phrases become more targeted, generate less traffic, but have higher conversion rates, the more they tend towards Buyer's Keywords.

The first SEO question that the content creator needs to ask themselves is simply this:

"What is the goal of my SEO activies? Traffic or Conversion?"

Search Engine Marketing, or SEM, is very closely related to SEO. Whereas typically, SEO is related only to the natural indexing of the content in the main search engine index, SEM tries to bolster the site's visibility through the use of SEO, Pay-Per-Click and Paid Inclusion strategies.

There is also a gray area between SEM and SEO which relates to Web 2.0 techniques to improve SERPs results. These include:

• Social bookmarking
• Tag and Ping
• Blogging
• Article marketing
• etc.

As Wikipedia notes :

"The term "Search Engine Marketing" was proposed by Danny Sullivan in 2001[8] to cover the spectrum of activities involved in performing SEO, managing paid listings at the search engines, submitting sites to directories, and developing online marketing strategies for businesses, organizations, and individuals."

There are some ethical questions that can be raised to deal with using these methods to gain competitive advantage, especially since it is relatively easy to use so-called Black Hat techniques to boost traffic.

Such Black Hat techniques include keyword stuffing, misrepresenting content, and link farms. Google, for one, has been very adapt at dealing with all of these, but monitoring trends across the spectrum still provides a full time job for many search engine optimization companies and search engine marketing specialists.