Where did the profits for the three neighbouring public stations come from? Who paid these stations??
As always in the civilised world except North Korea - companies which put ads in the media are the biggest source of income for radio, TV and net. When were you born that you are asking such silly questions - yesterday? Or you were born long ago but dropped from the moon just yesterday??? :):):)
If the radio station is popular, a lot of companies choose it for advertising and the income is high. If the station is not popular, we know what happens or do I have to explain such simplicities to you, too???? :):):)
PiS controlled radio stations and TV channels are low in popularity rankings coz they lie and manipulate 24/7. Even PiS supporters prefer independent media to get true info which was proven by polls.