Context : MicroFanBaseOfABoutiqueArtist
1000 fans is sustainable :
BillSeitz has a page on who he's a true fan of.
For me, musically it's Momus, and (at the moment) LuckyDragons, Vektroid and SofiaReta (people I currently like to buy from on BandCamp.)
I bought BardAndSoderqvist's two new books as e-books which you could say is fandom. I'd buy a new book by StewartBrand too. (I bought ChristopherAlexander in the past but not sure I can afford to buy his books on principle)
If he needed it, I'd regularly pay something to contribute to DaveWiner.
Apart from that it's basically things like the FreeSoftwareFoundation, WayBackMachine, Wikipedia, WikiLeaks etc. I've made donations too in recent years.
See also :