Foie gras is goose liver, so there are loads of geese required for that.
Goose itself is really good, too, and eaten in many places in the world, as has been said.
I know that eider geese are supposed to be the best geese for down, but I’m sure feathers from eating geese can used and correctly labelled as such.
Eider down is obtained by gathering down from the nests, which is why it is so expensive. The female lines the nest with her own down to insulate the eggs and chicks. If the down is removed before laying, the female will reline the nest before laying. Rather annoying to the birds I’m sure, but rather less so than being killed and plucked.
My grandmother plucked the goosedown from the geese’s breasts without killing them. I have goosedown comforters that contain goosedown that dates from the 1930’s.
PETA reports that this is a cruel practice but you have to consider the source. YMMV.
Uh, we eat geese in the USA. They’re yummy. People actually hunt these things, and they’re a bit meatier than, say, quail (which we also eat and are yummy).