Search Engine Marketing

I see SEM as a rather broad term. It's everything that can be done to utilize the technology of search engines with the goal of promoting a web site and increasing its traffic, its "stickiness," and, in the case of sites that promote a business (or are a business), increase profits. SEO, therefore, would be a subset of SEM.
Aspects of search engine marketing which I would consider to be outside the realm of search engine optimization include the following:
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