The Project for Excellence in Journalism has issued the report with this title for 2007, funded by the Pew Charitable Trusts. Lest you think it's all about news, it's also a goldmine of information on audience/readership, economics, ownership, etc. of various media that offer news products (of course, they would correctly argue that is all about news).
Just to highlight some interesting tidbits for the public broadcasting community to which I belong...
There are three charts (two here and one here) giving the footprint of the top commercial radio groups. Clear Channel has the most stations with 1,184, but if NPR-affiliated stations were a group, they would be #2, ahead of Cumulus Broadcasting's 300 stations. I don't know how many markets public radio reaches, but it must be close to Clear Channel's #1 ranking of about 190 (and, public radio reaches a number of places that aren't defined markets -- so let's claim #1 there). In revenues, Clear Channel and CBS Radio and #1 and #2, but public radio would come in a distant third, about 50% more than the next group, Entercom. So it's not poor little us -- just poor us (extrapolating to revenue per station).
Link: StateoftheMedia.org. Thanks to Gens Johnson of my staff for the link. --Dennis