As a non-profit organization, NPR is required to disclose its finances.

To wit:

For NPR's contributed support, fiscal year 2002:
Corporate sponsorship = 62.2%
Assorted foundations = 22.9%
NPR Foundation = 11.8%
In-kind contributions = 2.8%
Direct government monies = 0.2%
Individuals = 0.1%

Much of NPR's earned revenues come from program distribution fees and membership dues, that is, people pay for their programs. The only direct government funding it receives is in the form of grants competitively offered for individual projects. This amounts to less than 30% of NPR's annual revenue.

It's true that, as a non-profit, NPR can entice corporations to give bacause their contribution is tax-deductable. The same is true of all other non-profit organizations, including the American Red Cross and every church in the US. For NPR to receive corporate contributions must mean that they successfully compete in this market for corporate dollars and provide a product with which corporations wish to be associated.

NPR is also non-commercial, with the exception of the announcement of what corporation (if any) has sponsored a program at the beginning and end of the broadcast -- like the Mobil sponsorship announcement at either end of "Masterpiece Theater" on PBS. The "lack of commercial appeal", in this case, is simply the lack of commercials.

Regards--
Mary Anne