Last year at this time, I wrote a blog post called The Content Paradox. The basic idea is that, while the internet exists only because of content, original content creators generally are not rewarded for their content.
Further to that original post are a couple of related articles I just found (dated 2010) that calculate how much music an artist needs to sell to earn $1,200 per month, which is not a livable wage. This article, from InformationIsBeautiful.net, has a nice bubble chart that tells the sad story. This article, from the Cynical Musician, does the original math. The most egregious number is 4 million Spotify streams. Given the increasing popularity of these streaming services, it is pretty clear that the artists will struggle under this model and most will find it impossible to earn a living. For the vast majority, it clearly has become a labor of love.