Credit card, it's money they don't currently have but will be able to pay for in the future
Answer:
ACLU stands for American Civil Liberties Union :)
At that time, record sales, radio airplay and jukebox pick where the 3 ways of media diffusion for musicians. People would normally listen to music according to one of these 3 platforms according to their lifestyle and economic position. It is also known that certain music genres could be associated to one or another platform. Therefore, limiting the quantification of reproductions to only one platform would create a bias that would produce a distortion in the information presented.
