I think if you want to run it ad free, try keep costs as low as possible and maybe secure a few sponsors.
Anyway if what they are doing is working then I'm for it.
To answer the original question though, I have used it enough to benefit me, so a small donation is warranted.
X-rated Bob wrote
That's always a dodgy proposition because it puts you at the mercy of the advertiser. Advertisers may withdraw support (especially in financially tight times) or decide that they don't like some of your content and give you an ultimatum.
In the late 60s the FBI managed to shut down several "alternative" publications that they deemd to be "un-American" simply by persuading CBS to not place any adverts. Something similar happened with the International Times in 60s London.
Wikileaks is still going. The internet is bigger than any entity in that there is a community of "Anon's." Which is basically all of us. We are all that one person who will not be silenced or told what to do, like, or be. On the internet, Anon is king. That one person, is a few million people who have access to servers and hardware all over the world. Anon has the cooperation of other Anon's all over and while authorities can catch one, another will pop up and continue pushing for freedom of information.
Kind of like the movie, "The Three Amigos."