Evernote, the popular note taking app, released data about average annual revenue per user across different platforms. Evernote has more than 34 million users so it's a pretty good window into monetization trends.
Apple's iOS platform, on the iPhone and iPad, generated some of the highest revenues per user. Blackberry was surprisingly high, but this is likely because many of them are enterprise workers (whom a note taking app would appeal to). Android was at the bottom.
Evernote's data reaffirms that Android has a major monetization problem with app developers.

chart of the day, evernote monetization, june 2012