We know a lot about why listeners contribute to public radio, why the give when they do, and why the give certain gift amounts.
One of the great mysteries that remains, however, is why some stations get lots of contributions while offering few or no premiums while others can't meet their goals without selling a laundry list of mugs, t-shirts, gift certificates, and other stuff.
Is it that well-educated, societally-conscious listeners in some cities need more inducement than similar listeners in other cities? Is so, why would that be? Do they value the station less than their peers in other cities? Or is the difference on the station side of the microphone?