Here's a plot of the AAP sales figures for ebooks from November 2008 to September 2010*. Do you see the plateaus? There are 2 in this graph; one starts in January 2010 and the other in July 2010.
These plateaus are symptoms of market behavior that you can't see in yearly figures. What caused them? Why did the market go from fluctuations and incremental changes every month to irregular jumps? This is something everyone should be talking about.
I don't know why the plateaus are happening, but I suspect it's because of spikes in media attention that ereaders get. In January we had CES, where ereaders were the hot topic. And in July we had the K3 launch.
I could be wrong, so I'm waiting to see the data from October (when the Nook color was launched). If we see another jump, then I am probably right.
But what if I'm right, and then we see a long period without the jumps? What then?
* There's a blank spot for January because I couldn't find the numbers.