A good point, but kind of apples and oranges.
I've heard Rush gets 20 million listeners a week. I haven't heard the daily number, but I'll accept it.
A better comparison might be Rush and CNN, or even more accurate, Rush and NPR. CNN and Fox both run about 900,000 viewers in prime time, last I heard.
From this source, I got some numbers for NPR:
Morning Edition
(10.7 million listeners)
All Things Considered
(9.8 million)
Fresh Air
(3.3 million)
Weekend Edition - Saturday
(3.2 million)
I think the "Limbaugh Letter" has a circulation of about 400,000, but I'm not sure of that number.
