Regarding demographics for talk radio, see this link:
http://stateofthemedia.org/2012/audio-how-far-will-digital-go/audio-by-the-numbers/
Scroll about 3/4 of the way down and you will find this:
57% of N/T radio audience is 55+.
Only 39% is 25-54.
And for some agencies, interest doesn't stop at 54 ... it stops at 49 or 44. And, since it's a top 10 market, much of the ad money that's out there for Philly radio is agency money.
Also consider: Merlin's investors sold off the NYC FM because they weren't getting enough return on their investment quickly enough. I know, different format, failed attempt, etc. I'm just saying that the Merlin investors don't appear to be patient.
Now, also consider that stations in the top 10 markets pay well into six figures for the right to air Limbaugh. And, stations have many fewer commercials avails because many of them are kept by the network.
This is not a judgment on how many listeners IQ has or how good the station is. This is what I'm trying to say: No one should be overconfident about the longevity of this station based on one month's Arbitron rating, showing it beat WPHT in 6+ demos. It's got a tough road ahead ... tougher than any station that starts new with a pop or rock music format.
Also look at this: Cumulus is having trouble with N/T on FM in a couple of markets, and Clear Channel just dumped the FM simulcast of its Rush et al N/T station in San Diego.
There's a reason the news/talk boom on FM has been mostly around sports talk: It gets much better ratings demographics, and makes a lot more money. Conservative talk has been a much tougher sale on FM.