How To Choose a Hashtag - The hashtag (#) has become one of the most valuable assets in any modern marketing campaign. The brands that create the most effective ones and employ them well reap the benefits on Twitter. Those who haven’t invested the time and thought carefully about their hashtag(s) and how they are going to be used get predictable results.
The Correlation Between Social Signals And Search Engine Ranking - infographic
time on social media: Since 2006, the amount of time that the average person spent on social-networking sites has more than doubled, from 2.7 hours to 6.9 hours per month. More people are using social media, as well. While only 24% of Americans had a single social-media profile in 2008, 56% of Americans do now.