US citizens spend an average of 11 hours a week online, up from nine hours in 2006 and eight hours in 2005.
"As internet penetration continues to grow, the demographic profile of users continues to look more like that of the nation as a whole," said Harris Interactive, which carried out the telephone survey.
"It is still true that more young than older people, and more affluent than low-income people, are online, but nine per cent of those online are now age 65 or over, compared with 16 per cent of all adults who are 65 or over.
"Some 39 per cent of those online (compared to 47 percent of all adults) did not [spend] at least some time at college, and 13 percent have incomes of less than US$25,000 (compared to 17 percent of all adults)."
Overall the poll found that 97 percent of computer owners accessed the internet on a regular basis and over four out of five people now own a PC.