It really depends on how they do it. Do they try to guilt trip you into giving donations? Or act indignant and insult their listeners when cash runs dry? I don't have experience with NPR, but my guess is no.
Edit: I think the main difference is having or not having an expectation that you will be paid later for something that was provided for free.
Edit: I think the main difference is having or not having an expectation that you will be paid later for something that was provided for free.