"The whole 'buy mp3' idea always have been troubling for me because I can't figure out exactly what I actually buy there. What is it I purchase?" You purchased

"The whole 'buy mp3' idea always have been troubling for me because I can't figure out exactly what I actually buy there. What is it I purchase?" You purchased convenience -- not having to deal with filesharing systems that are polluted with various misidentified files, not having to try to figure out if the thing you are downloading is actually malware (for non-technical users this is often a challenge), not having to correct / create tags for the MP3 (artist/album/etc.), not having to guess at the quality of the audio (sometimes "lossless" actually means "preserved loss from some other format"), etc. For most people the convenience justifies the price.