It is axiomatic that a social media presence is vital for any artist, aspiring or established. The perceived impact of Gaga's Little Monsters or Justin's Beliebers, not to mention any number of supposed bedroom success stories, reinforces this.
The fakery of most bedroom successes, their apparent viral success actually fuelled by major record labels' spending, and the pronouncement by the ever tedious Ed Sheeran that he's taking a break from social media to focus on his ... 'art', indicate a flipside to the argument that web 2.0 sites offer a key opportunity and disruption of the established distribution and marketing route through record labels.
Keen has also established an academic narrative against the intrusive, exploitative nature of these data-mining sites who profit from selling user data.
The articles below (with some strong language) are a useful reminder of the volatility of social media, with dominant sites completely disappearing once they lose their fashionability or zeitgeisty status.