Asriel on 04 June 2014
I'd argue Mario Kart TV was included as a form of advertising, that's why the option to upload to Youtube is there. Given Nintendo haven't linked Miiverse with other social networks, it's a step forward for them to allow direct uploading to Youtube to one of Wii U's biggest releases yet.
Specific animations like Luigi's stares weren't put in because Nintendo knew they would lead to viral advertising, but they put mechanisms in the game that would make it easier for stuff like this to spread.
