Thanks David.
Based on your answer then, I think I have an interesting scenario.
KLAC runs a message on about a daily basis outlining the "fine print" of their station contests. Of course the message is delivered in a very fast-spoken format, indicating among other things, that station personnel, advertisers, employees of other radio stations and their families are not eligible. Also not eligible according to the spot, is anybody "not residing the in the station's TSA". I am sure the purpose of that is to eliminate non-local web users and over the air listeners who are not the targets of their commercial advertisers.
But the thought always comes to my mind when I hear this spot, What if someone listened in Upland or Rancho Cucamonga, a city not in their TSA (which you say doesn't exist) or the MSA, but clearly a Los Angeles suburbanite who can receive the signal well under normal circumstances (i.e. isn't DXing) but isn't technically covered by what I'll call the "local listening area (TSA)" rule. Would they really disqualify that person from winning a substantial prize if one was fairly won under the other rules and conditions for the contest? That would be a PR disaster. If they did go ahead and give the prize to such a person, would other listeners have standing to sue based on the station not adhering to its own contest rules?