US adults spent an average of 13 hours a week online in 2009, off slightly from last year, when average weekly online use was 14 hours, according to a poll by Harris Interactive. However, usage varies greatly: 20% of adult Internet users are online for only two hours or less per week, while 14% are online 24 or more hours a week.
The average time spent online has increased steadily: from seven hours in 1999 through 2002, to between 8 and 9 hours in 2003 through 2006, to 11 hours in 2007.
The age groups that spend the most time online are 30-39 year-olds (18 hours), those age 25-29 (17hours), and those age 40-49 (17 hours).
The number of adults online in 2009, 184 million (80% of all adults), did not change significantly from 2008; however, the number of adults online at home increased to 76%, up from 75% in 2008.
One-half (50%) of polled US adults online had bought something on the Internet in the previous month, including 62% of those age 30-39 and 56% of those age 40-49.
