Females now constitute an undeniable majority of the US Internet population. eMarketer estimates that there will be an estimated 97.2 million female Internet users ages 3 and older in 2007, or 51.7% of the total online population. In 2011, 109.7 million US females will go online, amounting to 51.9% of the total online population. Estimates from other research sources concur that females represent the majority of US Internet users, ranging from 53% (Arbitron and Edison Media Research, for Internet users ages 12 and older) down to 50.6% (comScore Media Metrix, for Internet users ages 2 and older).
More information and some funky bar graphs here. Via Sabreocracy.net.
