Confused. Looking at those charts makes me think that there is so much category-to-category variation that it defies logic to make such sweeping general statements.
It's hard to know for sure... it's all conjecture and hypothesis at this point... If you have specific objections to the data, I'd love to hear them... You are right that the generalization doesn't apply specifically to all categories.. but it does seem to apply in general and provides a great starting point for further discussion and analysis, IMO.
frossie - You nailed it. Pointing out the huge variation of paid vs free characteristics among App Store categories is something we try to convey in the article. The generalizations apply to apps on average, and are not proven in this report. Look for upcoming posts as we reinforce our case with much deeper analysis.