If you grew up in the pre-MP3 era, chances are you had at least one go-round as a member of Columbia House’s mail-order music club.
"..the clubs generally weren’t buying their records from labels and then selling them. Instead, the clubs would acquire the master tapes of records and press their own copies on the cheap. Moreover, remember those “bonus” or “free” records you got for signing up for the clubs? The clubs generally didn’t pay any royalties at all on those, which further slashed their costs..."