Interesting. I've worked with a lot of 3rd-party APIs and I liked Netflix's the best by far. They stuck to the REST concept the best of the ones I've seen and it made it very easy to start using it and to write a simple wrapper around it. I actually still use it as a reference when I'm building APIs. I hope they don't lose that.
Is that mystery device that jumped requests in October the PS3? That's when the disc-free update was released that used the new HTML5 interface. It fits.
It was probably the Canadian launch (late September).
I would venture it's a combination of disc-free PS3/Wii and the (Sept.) release of the iPhone app.
The apple tv was also released in October, that could also attribute to the growth.
That too (the atv increased my Netflix consumption 3-fold).
The influx of Netflix apps and devices just before the Holiday season seems to have been a very smart strategy.
Nice to see an absolute scale in number of requests. It seems that the mystery device making 50% of the API calls was introduced or gained Netflix playback in October 2010 :)