I’ve been having an ongoing conversation with readers and friends over digital rights management, or DRM. Yes, we all agree, it’s evil. And someday, the Evil DRM Empire will be overthrown and freedom will reign.

That day, however, has not arrived. But Ben Drury of the British music download service 7Digital says that selling DRM-free music is working so well for the company that he believes DRM will be overthrown next year.

“By next summer all four major labels will have removed DRM from MP3s,” Drury told The Register.

Drury believes killing DRM, which restricts downloads from playing on non-compatible players, is saving digital music. His evidence: 7Digital says DRM-free music sales now outnumber DRM-enabled music 4-to-1. He also credits EMI, the first major label to offer its catalog DRM-free, with the shift.

“It’s MP3, absolutely,” Drury said. “People understand that MP3 works everywhere — that isn’t true for AAC (tied to Apple’s iTunes and iPods) and certainly not for WMA (tied to Windows Media-compatible devices).”

Jeff Bezos, the Amazon.com CEO, said recently during an earnings call at the end of October that “everybody loves the DRM-free format.” Amazon launched its DRM-free music store, AmazonMP3, at the end of September. In just 30 days, it was believed to have become the No. 3 online music store behind iTunes and eMusic because it sells music that can play on any device.

“I would just say that we’re happy with the early results that we’re seeing,” Bezos said. “We’re getting terrific feedback from customers. Everybody loves the DRM-free format, so selling MP3s is very successful for us.”