SEO,SMO or SEM

[nptifitness]

SEM is a much broader term than SEO, and actually includes SEO as one of its techniques. SEM is all that a company can do to advertise itself on a search engine, including paid inclusion and other ads.
SEO - PROS
1> Organic listings are a trusted source of information, believed to be unbiased and indexed solely by the automated methods of an objective third-party
2> Natural search traffic provides a steady stream of traffic over time
3> Costs are frontloaded; once pages are optimized for organic search, low ongoing maintenance fees make it cost-efficient for marketers on a limited budget
Social media optimization (SMO) Social Media Optimization is the methodization of social media activity with the intent of attracting unique visitors to website content.

Social media optimization is related to search engine marketing, but differs in several ways, primarily the focus on driving traffic from sources other than search engines, though improved search ranking is also a benefit of successful SMO.