First reported as a “credibly sourced rumor” by Shelf Awareness earlier this morning, Amazon announced that it has acquired Brilliance Audio, the largest independent audiobook publisher in the US, from owners Michael Snodgrass, Eileen Hutton and a private equity group, for undisclosed terms. Publishers Marketplace further reports that as part of the audio expansion, Amazon’s subsidiary CustomFlix will now support both standard CD and mp3-CD audiobook formats in its “disc on demand” service–the equivalent of print-on-demand manufacturing for audio titles. Greg Greeley, Amazon’s vice president of books, notes the audiobooks field “continues to see good growth in the indsutry and great growth at Amazon,” even thought “there isn’t a full breadth of selection.”

The purchase is particularly notable because it’s the first time Amazon has acquired a traditional media company that licenses intellectual property. Brilliance Audio will continue to operate independently under the Snodgrass’s leadership and its operations will remain in Grand Haven, Michigan.