Just to be perfectly clear, payola is illegal. It has been an on-going issue for decades, but most radio stations are NOT paid to play songs. When payments are made, they are normally to the DJ or program manager, not the radio station, itself.
Radio stations pay NO royalties to the artists. They do pay to the publisher and the author of the song through a licensing organization. In the US this is usually ASCAP American Society of Composers, Authors and Publishers) or BMI (Broadcast Music Incorporated). For decades the artists/performer has been held to receive "payment" in the form of promotion of the performance by air-play and deserving of no other compensation.
Streaming services (e.g. Pandora) claimed that they were providing the same promotional service as radio and should have the same exemption as radio, but the courts rejected this.
I'm a former DJ at a commercial station and was never offered payola. The boss (CEO) made it clear that anyone accepting payment to play any song would be summarily terminated. (I think he meant "fired", but he might have preferred a more drastic termination.)