A byproduct of the downturn in sales over the past few years has been the recent introduction of digital only sales by record labels. In recent months, albums by Carter's Chord on ShowDog Nashville and Jennifer Hanson on Universal South, for example, were made available to listeners first only on the web.
There probably are several reasons. First, the records are in the can, and like any commodity, just sitting there on the shelf means zero revenue for labels. Record labels are loath to put out CDs without a hit single. Even without the benefit of a hit for the artist and labels, by at least putting the music out on the internet for buyers in an extremely inexpensive way for labels means they recoup at least some of their expenses. This may not be ideal f or the labels or for artists, who probably don't receive the full marketing push from the labels. In some cases, the releases are slated to hit retail outlets later (Carter's Chord). Of course, in some cases, the music never gets beyond the internet (Susan Haynes' "Crooked Little Heart," for example).
Chances are the labels also are hoping for lightning in a bottle with some of these releases - meaning that thanks to the internet, an artist or song could develop a big buzz, leading to bigger and better things.
While certainly limiting the choices of consumers who don't buy online, the benefit here for those who do is that they are able to get their ears on more music than they would have in the days of only having record stores. It may not have been the intent of the labels originally, but getting the music out there benefits all.