[singron]

What about public radio and TV? There are some sponsors and government funding, but I think they are largely based on private donations.

[autarch]

http://www.npr.org/about-npr/178660742/public-radio-finances

Individuals are the largest single source of funding, but they don't make up the majority of it, at least for NPR. Corporate sponsorship is the next biggest piece, and while it's not very intrusive, AFAIC the sponsorship messages on NPR are basically ads (very tolerable ads, but still ads).

[robbrown451]

I often find the sponsership messages less tolerable than ads, at least when talking about public TV.

[mikeash]

Not sure what you'd count as "largely," but this shows about a third of the funding for US public radio coming from individuals: http://www.npr.org/about-npr/178660742/public-radio-finances

And unfortunately, the messages they run to acknowledge corporate and foundation sponsors get more and more ad-like with each passing year.