CNFS NFS sharing isn't known. Traffic doubles every 15 months. Probably 94 out of 100 most popular newsgroups are pornographic some way or other. Some of them are warez. Can't be disclosed.
People read more articles with a fast line.
Having three really good feeds is optimal. Four is 2nd best. Having an extra feed smoothes expire. Users dislike slow propagation of their own postings. Having downstream is a bad solution because it isn't transparent to users.