According to a mid-year report released last week by the RIAA, vinyl music sales brought in almost $60 million more than ad-supported streaming services during the first half of 2015. Vinyl album and EP sales generated $221.8 million in value from January to June this year, a 52 percent year-over-year increase. Ad-supported streaming — which includes services like YouTube, Vevo, and Spotify's free version — grew too, but not as quickly: it brought in $162.7 million in revenue, a 27 percent year-over-year increase. The gap between vinyl sales and ad-supported streaming is just one piece of the music industry's increasingly complicated revenue puzzle, one that now consists of three near-equal parts: physical sales, downloads, and streaming revenue.

The industry's bigger picture hasn't changed much since the RIAA released its full 2014 report in March: increases in digital revenue are sustaining the industry in the wake of flagging CD sales. Permanent downloads are still bringing in the most money, making up 40 percent of total revenue during the year's first half. That's not going to remain the case for long: total streaming revenue has already overwhelmed the value of physical sales, and it's starting to cannibalize permanent digital sales too.

Streaming's growth is just going to keep accelerating

The combined proceeds from digital radio revenue, subscription services, and ad-supported streaming eclipsed $1 billion over a half-year period for the first time ever, and each of the subdivisions mentioned above grew faster than every major category save vinyl sales. And streaming's growth is only going to accelerate in the time between this report and the RIAA's next missive: Apple Music was released on the very last day of the analysis period, and it's poised to bring in millions more paying subscribers.

"The data continues to reflect the story of a business undergoing an enormous transition," said RIAA chairman and CEO Cary Sherman. "The product of music and the extraordinary roster of artists represented by today's music labels remains in high demand... at the same time, intense demand and billions of streams does not always equal fair market rates or a fair playing field. Addressing that is an essential element of fulfilling the enormous promise of today's digital marketplace."