Even serious, mainstream talk radio programs do similar things, but it's usually employing shill callers to fire up the listeners. Fired up listeners means more callers which, in theory, translates at some point down the line to the selling of more on-air advertising.
Jacor (now evolved into IHeart) was well know in the industry for using on-air talent from other out-of-the-area affiliates to play the shill caller role. It was not uncommon for me to hear local talent (from WLW here in Cincinnati) making shill calls to shows on Jacor stations in other parts of the country during my travels. Conversely, there was a sports guy from some station out west (Phoenix?) who called WLW's nightly sports talk show a couple times a week to piss off the Reds/Bengals fans. Of course he claimed to be from a Cincinnati suburb. Even as recently as a year ago WLW had a shill passing himself off as a high society, multi-millionaire type who would belittle the people/city of Cincinnati. There were actually listeners who would call in and want to fight the guy!