They offered first class seats at much reduced fares compared to their competitors, didn’t they?

I believe so, or you could upgrade for really cheap. They also had the “free Vegas stopover” gimmick. Being that their hub was in LAS, if you flew between any 2 cities (that wasn’t originating or terminating in LAS) you were entitled to a free stopover in Vegas at no extra cost. Pretty good deal, if you ask me. One of my cousins flew them between LAX and JFK and took advantage of this.