New research from the NPD Group indicates that nearly 90% of initial iPad sales are incremental and are not cannibalizing the PC market. 

"Contrary to popular belief, the iPad isn’t causing cannibalization in the PC market because iPad owners don’t exhibit the same buying and ownership patterns as the typical consumer electronics customer," the group says. 

NPD found that only 13%t of iPad owners surveyed bought an iPad instead of a PC, while 24% replaced a planned e-reader purchase with an iPad. 

An a more obvious note, the group also found that iPad owners tend to own more Apple products, and are early adopters of other new technologies. 

"Early adopters, like iPad owners, follow a traditional pattern of consumer behavior; they purchase products because they want them, not because they need them," said Stephen Baker, vice president of industry analysis at NPD. "However, as Apple increases iPad distribution and consumer interest peaks, the profile of an iPad owner is much more likely to mirror the overall tech population. When that does happen other tech products with similar usage profiles as the iPad, such as notebooks, netbooks, and e-readers will come under increased pressure from the iPad. Until then, however, most iPad sales are likely to be incremental additional technology devices in the home, rather than a one-for-one replacement of a planned purchase."

There’s no doubt that iPad sales will continue to climb, as will similar offerings from other manufacturers, but it doesn’t look like they’ll be replacing the PC anytime soon. 

50% of the first wave of iPad sales came from people who own Apple computers. That number dropped to 45% among later sales, the group says.