Tom Moon and Don Was on Liner Notes

"When somebody downloads an album from most places on the Internet, what they get is a file containing fairly decent digital representation of the music and a tiny image of the front cover. For those who come to music to expand their horitons, it’s essentially a dead-end. More than that, the absence of information sends a signal: The folks who were involved in the creation of this work are relatively meaningless, just a shade more important to the end-user than the factory worker who bolted the player together. "

Go read the thing! Liner notes provide more than fodder for fact geeks. More importantly, they provide info on who made/provided what on a given record, and can point those interested in the direction of these other musicians' work, should they be so inclined. Which we often are. Of course, a lot of information on recordings is available online nowadays, on Wikipedia, discography pages and so on, but when you buy a physical record, most of this info comes with the package. Downloading files, in order to get this information, you'll have to do exstra work.