“There’s a renaissance for spoken word content and our media diet is expanding, but as the landscape becomes more saturated, audiobooks face greater and greater discoverability challenges,” said Tom Webster, v-p of strategy and marketing at Edison Research, during his keynote speech at the annual Audio Publishers Association meeting on Wednesday morning.

According to Edison’s most recent survey of audiobook listeners, 67 million people have listened to one audiobook in the past year. Of these, 18% were labeled as “frequent listeners,” having listened to four or more audiobooks in the past year. Of these, 56% were men and 44% are women. Eighty percent of these listeners had paid for their most recent audiobook, rather than streaming it from YouTube or downloading it for free. They are also discerning customers, with 74% saying it is important to listen to a sample of the audiobook before committing to it and another 59% saying it was important for them to get ancillary material with the audiobook, like author interviews or sample chapters of forthcoming titles.

Unsurprisingly, there’s an increasing preference for downloading digital files or streaming audiobooks, with digital now accounting for 71% of the market, with the preferred means of listening being the smartphone. As of today, 27% of audiobook listeners subscribe to an audiobook streaming service, such as Audible or Audiobooks.com.

Webster underscored one growing trend: the use of voice enabled wireless speakers, like the Amazon Echo and Google Home, to listen to spoken word content. Among audiobook listeners, 25% own such a speaker. “But this poses its own set of challenges, as the user must call out a specific piece of content to the speaker,” said Webster. Still, the use of speakers is likely to grow, for as Webster noted, most audiobooks are listened to at home, rather than in the car.

When it comes to content, audiobook listeners favor mysteries, thrillers, suspense titles and popular fiction titles. Health and fitness, as well as business titles were the least favored genres. Among frequent listeners, 47% said they enjoyed listening to a specific narrator, “so there is considerable narrator loyalty,” said Webster.

The growth in the popularity of audiobooks has been accelerated by the popularity of podcasts, which serve as a “gateway drug” to audiobooks. Not only do podcast listeners generally consumer twice as many audiobooks per year as non-podcast listeners, and “though they listen to a lot of free content, are also among [audiobook publishers’] best customers,” said Webster.

The seven-part podcast S-town was downloaded 40 million times, making it the most popular podcast of all time. “But it is really just an audiobook, broken up into seven parts,” said Webster. The opportunity, he said, was for audiobook producers to pursue podcast listeners by experimenting with formats — he advised listening to NPR’s 10 minute morning news briefing Up First, and to consider advertising audiobooks in podcasts. “Cross-promotion is the secret sauce.”