It would be difficult to find a private equity company that has more faith in the audiobook market than Shamrock Capital Advisors. The firm was the underbidder when Wasserstein & Co. bought Recorded Books in January 2014, and when Wasserstein was looking to sell Recorded Books 18 months later, Shamrock stepped up and did the deal. Shamrock made its most recent move in the audiobook market in April when it simultaneously announced the acquisition of Audiobooks.com, the app-based audiobook streaming and download service, and the creation of RBmedia, the company that now holds Audiobooks.com as well as all of Recorded Books’ old divisions.

With the Audiobooks.com purchase, RBmedia, based in Landover, Md., now employs nearly 400 people across all eight of its brands, according to John Shea, chief product and marketing officer, and total combined revenue for the company is in the “nine figures.”

The purchase of Audiobooks.com and the formation of RBmedia represent a progression of the original vision that Shamrock had for audio when it bought RB in August 2015, according to Shea. “We could see three major trends happening in the market driving the consumption of spoken audio as well as other forms of digital content,” he said. The first is the desire of busy consumers who don’t have time to sit and read books but want to be able to multitask—drive, commute, exercise—while listening to entertaining content. The second trend Shea cited is the evolution of mobile technology and proliferation of mobile devices, which enables people to listen to spoken-word content more easily than ever. The final trend is the recent strong growth of the digital audiobook market and the mass adoption of podcasts, which are, he said, “a gateway into the consumption of other audio forms.”

“Bringing Audiobooks.com into this new organization of our brands is a great opportunity to further expand the consumer reach that Recorded Books and our other imprints had,” Shea said. “This acquisition means we have a very compelling story we can tell authors, agents, and publishers.”

In addition to a catalogue of 30,000 proprietary audiobooks from its own publishing imprints, RBmedia partners with various publishers and content producers to offer a portfolio of digital media that includes e-books, magazines, and educational titles and spans more than 700,000 titles. RBmedia content is distributed through more than 10,000 library partners via its RBdigital cloud-based platform, as well as through such consumer resellers as Audible. Thanks to the Audiobooks.com purchase, the company will now also sell directly to consumers.

The six RBmedia imprints that generate content and the two that develop and operate the technology and distribution platforms can each be thought of “as essentially a division within the RBmedia organization,” explained Shea. “They work very closely together and are run by an integrated management team,” under the direction of Tom MacIsaac, RBmedia CEO.

Each of the content brands brings a different strength to the table. In the U.S., Recorded Books, founded in 1979, had built a reputation as a quality producer and distributor to libraries of unabridged audiobooks. By 2014, Recorded Books had transitioned into providing other digital content and had operating subsidiaries Wavesound in Australia and W.F. Howes in the U.K.

RBmedia’s other content companies are Tantor Media and HighBridge Audio, both acquired in 2014, and Christianaudio, which offers downloads and CDs of original Christian fiction, personal growth and inspirational titles, and audio Bibles, as well as products from other Christian publishers through its subscription service.

Shea said more acquisitions could be forthcoming. “We see many opportunities to acquire companies that will provide us with new content sources as well as help us expand the capabilities and reach of our technology platform. Since we have the backing of a major private equity firm, we have the resources to make future acquisitions happen.”