The only way that NPR can be said to be "financially successful" is that it is subsidized by the taxpayers.
Isn't that interesting? The only way liberals can maintain a nationwide syndication for their views is to ride the backs of American taxpayers!
I believe that all of these shows are primarily associated with "home" NPR station and then syndicated across NPR station by station. They are not directly funded by NPR as it exists in DC(?). There may be indirect funding through the network transmission of the programming and by local government funding of individual NPR stations.
It would be interesting to follow the money and see which levels of government provide what fraction (and total $) of the funding for the various shows.