This is has been something I've been thinking about a lot lately and I think it would be a good subject to get some discussion on. Are we living in a post-Billboard society at this point in time? While the masses have always followed music charts and they still do make a huge impact in regards to music sales, I feel like ever since the advent of the internet and services like Pandora or last.fm, a pretty large sum of people have started to drift away from simply listening to what's currently popular on any given chart and have begun branching out and finding their own personal tastes in music. You see this with the rise of artists like Azealia Banks or Marina and the Diamonds. They've never/rarely charted, yet are massively popular with the internet crowd.
What I'm getting at is, while Billboard/Nielsen are still useful, they don't seem as necessary as they used to be. I've noticed the decline mostly in the past four years or so.