According to a comScore study,

Women on the Web: How Women are Shaping the Internet,

social networking sites reach a higher percentage of women than men globally, with 75.8% of all women online visiting a social networking site in May 2010 versus 69.7% of men.

Globally, women demonstrate higher levels of engagement with social networking sites. Although women account for 47.9% of total unique visitors to the social networking category, they consume 57% of pages and account for nearly 57% of total minutes spent on these sites. Women spend significantly more time on social networking sites than men, with women averaging 5.5 hours per month compared to men’s 4 hours.