Nielsen asked tablet owners how their usage of other devices had changed since they joined the tab/pad army. More than a third (35 percent) said they use their desktop computer less or not at all, while 32 percent said they use their laptop less. Nielsen reports 77 percent of tablet users use a tablet for tasks that they previously would have done on a laptop or desktop.

The most popular reason cited for favoring tablets is unsurprising: they're easy to carry around. Thirty-one percent of tablet owners responded that portability was the main reason for using a tablet over a laptop or a desktop. Ease of interface or operating system and fast start-up and power-off times were the second and third most common reasons given.

Another interesting finding is that tablet-sharing doesn't seem to be the norm in American households - only 43 percent said they share their tab with others under the same roof, and half said they were the only ones using their particular tablet.

As for the effect on other devices? Twenty-seven percent of respondents said they pick up their e-readers less often, and a quarter of respondents have cut back on their portable game console use. Tablet purchases seem to have the least effect on the use of Internet-connected TVs and smartphones.