Kindle sales now account for a huge percent age of book sales at Amazon

Publishers Lunch says that Amazon CEO Jeff Bezos said "Kindle sales are now 35 percent of books where we have Kindle editions" and print editions of the same title. PL says this is “more than three times the ratio that Amazon had reported previously, first in October and then again in February when Kindle 2 was announced. The initial reception at numerous trade publishers, executives tell us, was deep skepticism. But as sales departments crunched numbers, in many cases the data has confirmed the general range of Amazon's report.”

The most interesting part of the article was this unanswered question:
“Do Kindle Sales Cannibalize?
The big unresolved question for many houses is whether this spike in Kindle sales is additive or cannibalistic. (Amazon did not update their contention from last year that Kindle customers "buy the same number of physical books going forward as they did before they owned a Kindle. And then incrementally, they buy about 1.6 to 1.7 electronic books.") One executive believes strongly that, while their house's total Amazon sale on big books is rising when you include Kindle and print editions, the Kindle spike is taking market share away from other retailers' print versions (though this point will be hard to confirm until after returns are taken on recent releases). Other houses are just beginning to analyze the extent to which these sales are additive or cannibalistic.”