I live in Sweden and there are barley any game related commercials here except for consoles and WoW. I do not know much about commercials in USA or UK.
But it seems to me that Nintendo are not reaching to your age group rather they advertise in their "traditional" places: places where kids and families are.
Miyamoto went to youtube channels like ijustinegaming https://www.youtube.com/user/ijustinegaming and Smosh Games https://www.youtube.com/user/SmoshGames before christmas to talk about new and upcoming games.
They get Mario Kart toys to McDonald's Happy Meals.
Nintendo top some list over holday commercials http://marketingland.com/nintendo-ebates-com-score-top-holiday-ads-112366 with an ad targeted at families.
"Without" advertising Nintendo manages to sell millions of amiibo toys http://wiiudaily.com/2015/01/nintendos-new-big-hit-amiibo-sales-are-twice-of-super-smash-bros/.
They are also on APEX: https://mobile.twitter.com/apex_series/status/553614352641970176
...and on twitch: http://www.twitch.tv/nintendo
