Search engine marketing (SEM) is just an umbrella moniker for paid campaigns or anything other than reliance on organic search. SEM goes by Pay-Per-Click (PPC), Cost-Per-Click (CPC) and various other acronyms and is available on a seemingly infinite number of platforms. Google Adwords is the market leader for obvious reasons, but Bing/Yahoo certainly have their place with considerably less volume but higher CTRs. Professionally managed paid search efforts can work seamlessly with organic strategies or replace them entirely if the value or need for both isn't there. A holistic approach is ideal and encompasses paid, organic and social channels all in one cohesive package.