I think for the furthest Philly signals received will either be KYW or WPHT as FM just isn't going to get out like AM does. So I've listened to AM1210 WPHT in Atlanta Ga, and in Portsmouth, NH and enjoyed hearing the Phillies games and the hometown news and local spots, etc. at night. Sort of a taste of home. When you live away from the Philly/Wilmington/Trenton metro area, you realize how great this area is.
Of course with today's internet and streaming online, my guess is all of WPHT's talk programming, other than the Phils is carried online meaning anyone can listen now from anywhere in the world, just as they can do with most other radio stations in any market. I've listened to Radio Times on WHYY-FM and Marty Moss-Cohan (sp) gets quite a few callers from the mid west, and the west coast, New England, etc. Obviously they're listening online, but still it's so cool that today we can search out radio stations that we could never listen to here, like I listen to On Point, a talk show with Tom Ashbrook from WBUR in Boston, online. I've listened to a great Classic Country station KMPS from Seattle online. They play country from the 1950's through the 1990's. There are some great classical music stations, oldies stations, etc, that are just great ON line.
My guess is, some day, Arbitron will start rating online radio as well as terrestrial over the air radio, because with the I-phones, etc, those folks can listen to those online stations anywhere, so why settle for a mediocre Oldies station like WOGL when there's some great real Oldies stations online, or put up with country top 40 of WXTU when you can get 50 years of great country with KMPS online. Now folks like me who only can listen online with their desk top computer are limited, but someday the prices of all that will drop enough where even Luddites like me will get a Blackberry, I-phone, etc, and even listen online elsewhere when not at home or at work with my work computer. The real break though, where I believe OTA radio minus their online service, will be severely hurt is when you can go online with your radio in the car and get KMPS or WBUR in your car without the expense of buying a satellite radio. Maybe your I-phone or Blackberry would be able to plug into your car's sound system and with some sort of WIFI on the highways, etc, you'd be able to listen to your favorite online radio station. Talk about competition. Then old time radio as we know it will be in serious trouble unless they have something really good like the Phillies or Eagles, or make themselves into a really great Oldies or Country, or whatever station that would appeal to a nationwide audience. Granted, for local talk, news, weather, sports, the hometown stations are where its at and that makes them valuable too. So then when you travel for business, you can still hear the local talk, news/weather/sports/business report, etc, on your local station online even in your car. That's my spin.