This document summarizes a study on the effectiveness of social media marketing. The study analyzed Twitter activities and sales of Fortune 500 companies to identify correlations. It also surveyed 1000 college students to determine if Generation Y is the main target and how social media usage relates to purchasing. The study found social media marketing effectiveness depends on message quality, company involvement, and integration with other platforms. A complex analysis is needed to accurately measure return on investment. Generation Y are major social media users but not necessarily the main target audience.