I think Writer is a pretty successful app that is in the charts (and Apple may have also promoted it at various times). Maybe the dynamics are slightly different for less successful apps that are less exposed in the App Store?
I noticed a similar trend from my much less successful app. I tried price variations from $0.99 up to $10. It seemed that no matter what price I set, I would average sales of around $10 per day.
The trend lasted for quite some time until someone released the app onto the pirate channels, at which point my sales almost disappeared. I guess a free option can change the dynamics.
The trend lasted for quite some time until someone released the app onto the pirate channels, at which point my sales almost disappeared. I guess a free option can change the dynamics.