Internet marketing can also be broken down into more specialized areas such as Web marketing, email marketing and social media marketing:
Web marketing includes e-commerce Web sites, affiliate marketing Web sites, promotional or informative Web sites, online advertising on search engines, and organic search engine results via search engine optimization (SEO).
Email marketing involves both advertising and promotional marketing efforts via e-mail messages to current and prospective customers
Social media marketing involves both advertising and marketing (including viral marketing) efforts via social networking sites like Facebook, Twitter, YouTube and Digg.