Both, of course. And everyone else. But there are some strange numbers circulating. While my impression is that particularly teens and millenials value YouTube higher than TV and anything else - note that 3 of the worldwide top 5 channels deal with gaming, that teens have a YouTube-biased view of celebrities etc., Nielsen statistics say that YT reaches more 18-34 than any cable network - other studies show a different "main audience". A research published by YouTube itself for Germany, where 1500 people were asked, is headlined that the common German YouTube user would be over 30, has a high average income, is digital savvy and likely to go out and spend money on restaurants and gadgets. Sounds strange to me. Very much like a "don't spend money in print or TV, buy YouTube ads"-cry to advertisers as they have teens and millenials in their pockets anyway.
Odd German stats:
YouTube viewership by age group and category like comedy, sports, news, music etc.