I don't have a turtle in this race and I'm not a statistician but I do understand the dangers of extrapolating from a days worth of data. It's not a large enough sample and I don't think Hugh should have published the conclusions that he did. I do understand the void of data that indie authors are working from though so there is a lot of excitement over having real data. In the spirt of this I'll extrapolate my own inaccurate conclusions.
What did jump out at me were the pie charts that show that (on that particular day) Amazon was able to take the Amazon published 4% of the titles to 15% of the daily unit sales. I knew that Amazon's targeted marketing was a real advantage but if that's typical it's huge. On the same day the big publishing houses (BPH) were only able to take 28% of the titles to 34% of the unit sales, this despite their traditional advantage of author brand recognition. In comparison the single/small/medium publishers (Amazon Publishing primary competition) had a combined 33% of the titles but were only able to generate 8% of the unit sales. It makes me wonder if Amazon really has that much power to direct sales where they want. If so it's not smart to make an enemy of them when you're trying to sell books.
This got me thinking about the "slowdown in ebook sales". It's been recognized that the data isn't complete because it excludes Amazon's proprietary data and indie sales (assumed to be insignificant). Hugh's data shows (on this particular day) that Amazon was able to take 35% of the titles to 39% of the sales which is hardly insignificant. It's more unit sales then the BPH. I bet that made the BPH sphincters contract.
Over the last 4 years the BPH have taken every possible opportunity to pick a fight with Amazon but at the end of the day it was recognized that the agency pricing was good for Amazon, they were collecting a guaranteed 30% off of higher priced books so it made good business sense to direct customers to those offerings. When agency pricing ended the 30% went away and it's no longer in Amazon's business interest to direct customer's to the lower margin sales. Why not direct sales to indie offerings at a higher margin and decrease your reliance on the self declared enemies. At the same time reports start coming in that BPH ebook sales growth is slowing. Is it possible that ebook growth has been continuing to grow? More data will be interesting. I wonder if Amazon will cut off the data feed that Hugh has been using.