Social media marketing refers to the process of gaining traffic or attention through social media sites. Social media itself is a catch-all term for sites that may provide radically different social actions. For instance, Twitter is a social site designed to let people share short messages or “updates” with others. Facebook, in contrast is a full-blown social networking site that allows for sharing updates, photos, joining events and a variety of other activities
One of the key components of SMM is social media optimization (SMO). Like search engine optimization (SEO), SMO is a strategy for drawing new and unique visitors to a website. SMO can be done two ways: adding social media links to content, such as RSS feeds and sharing buttons -- or promoting activity through social media by updating statuses or tweets, or blog posts.
SMM helps a company get direct feedback from customers (and potential customers) while making the company seem more personable. The interactive parts of social media give customers the opportunity to ask questions or voice complaints and feel they are being heard. This aspect of SMM is called social customer relationship management (social CRM).