“For Apple, the iPhone is a sale that keeps on giving — at least in the U.S. Once a customer has bought one, he or she is likely to come back for another, usually within two years, when that contract expires,” Philip Elmer-DeWitt reports for Fortune.

“The iPad is a like a big iPhone in some respects,” P.E.D. reports. “In terms of how often they are traded in for a new model, however, and what happens to the old, they may be more like Macs (which tend to get replaced every 2-4 years) or, worse still, TVs (5-10 years).”

P.E.D. reports. “‘We think Apple would prefer the iPad become a big iPhone,’ the report concludes. ‘We suspect, though, based on recent CIRP data about how buyers use them, that it’s as much like a Mac, TV, or iPod, with less frequent replacement.'”

Read more in the full article here.

MacDailyNews Take: Suspicion is not hard data.

iPad was only released on April 3, 2010. While not typical Apple product users, we’ve already had, on average, four iPads per family so far (1st gen., 2nd gen. 3rd gen. and Air; none of us happened to purchase a 4th gen. iPad).

Let us know by voting in the MacDailyNews poll (left column on main site, menu option in app) how long you use/plan to use your iPad before replacing it.