I am referring to the Revenue Sources image (second on the page):
39% Station dues and fees
23% Corporate sponsorships
9% Distribution and satellite interconnection
-----------------
71% of revenue from commercial activities
>The most significant component of station dues and fees revenue is the charge for carrying our premier newsmagazines - [list of show names].
>Non-newsmagazine program fees (for example, [show]) make up the next largest component of station dues and fees revenue.
Calling most of items commercial is a willful misconstruction of the structure and methods use by NPR. Corporate sponsorships is functionally no different than individual member contributions at the station level, station dues are how costs are apportioned and passed on to member stations.
However, If NPR is using excess satellite airtime to carry non-NPR programming, that could be considered commercial activity, yes.
From the view of NPR, revenue from "station dues and fees", primarily come from charging for access to NPR content, not member donations. It is strictly commercial activity: NPR is producing content and selling it.
I think corporate sponsorships are different (if they were functionally the same as another category, they would have been aggregated there). For one, corporations get advertisement time.
>Non-newsmagazine program fees (for example, [show]) make up the next largest component of station dues and fees revenue.