Booklr has published a survey of the top 100 Kindle books v top 100 Nook titles. 35% of the top Kindle titles were free or under two dollars – vs. 0% for the Nook. 40% of Nook’s top 100 were $10 and up, vs. only 27% of Kindles.
Booklr bills itself as “a data and analytic platform that delivers actionable insights to book publishers about their market, customers and retail partners.” (Their charts are more concise.)
My conclusion: Kindle buyers buy what’s cheap. Nook customers buy what they want.