Every series you've ever watched with the Apple TV -- of course, they keep track of what you watched with them!
(/s).
Man, how I wish there was a Netflix setting "omit things I've already watched", since I know they already know this.
I can't help wonder if they are just afraid of the offering looking more bare, or is this really such an uncommon desire to want to see "new to me" stuff and not repeat things?
It would be a horrible user experience if it didn’t keep track of the series I’ve watched and where I was in shows so I could pick up and watch where I left off on a different device.
This isn’t the iPod days where you would sync your watch history with iTunes.