You don't pay money for tracked stuff. You pay for the ability to has this opportunity + your personal profile, lists, recomendation etc.
Just imho
I pay money for tracked stuff you say, but they're basically tracking what trakt.tv already does, hooking into their recommendation engine, and then serving the result in some nice sauce.
I think marketingwise this is brilliant, but I would never pay money for it. As said above, this is a nice to have feature on top of a lot of other things. Content availability being the most important IMO.