The 500 or so Apple (AAPL) iPad owners who responded to Business Insider’s survey last week were self-selected, so they’re not what you would call a scientific sample. But their answers, posted Saturday, are instructive. Among the results that caught our eye:

• 77.6% say they use their iPad more now than when they first got it. Nearly 85% are on it more than an hour a day and roughly 10% use it 5 hours or more daily.
• Although only 28.9% say it has become their primary computer, replacing their laptop or desktop, when asked on what device they spend most of their personal computing time, nearly one in three answered the iPad.
• Nearly 40% have downloaded 20 to 50 apps. More than 16% reported downloading 50+.
• Nearly 75% read books on their iPads, 50% using Amazon’s (AMZN) Kindle app. iBooks was a close second, at 42.4%

For the rest of the results, click here.

[Follow Philip Elmer-DeWitt on Twitter @philiped]