As you know, Billboard changed their charts on December 3rd. We received a number of questions about the new Billboard 200 consumption chart, which now combines album sales with downloads and on-demand audio-only streams from those albums. Based upon test charts, the weightings are over 75% albums, under 20% digital downloads, and under 10% on-demand audio streaming.
Separately, the Billboard Hot 100 singles chart formula has been revised (effective December 6th) and places sales, airplay and streams each in the 30-35% range on average, with sales slightly ahead of airplay and streams in weight. This target ratio for streaming was increased from the beginning of 2014, where it was approximately in the mid-20% range.
As of the February 14, 2015 chart, Amazon Prime will now incorporated into both charts.
The full details and methodology are included in this Billboard chart methodology guide.