Search Engine Marketing (SEM) involves a variety of different tactics and strategies to gain search engine visibility, namely Search Engine Optimization (SEO) and Pay-per-Click (PPC) advertising. SEO encompasses everything that happens on your site to communicate with and give indicators to the search engines, from proper tagging, to quality content, to optimal site structure. Taking it a step further, SEO also encompasses all things that happen off-site such as linking, content, social media interaction, and…