There hasn’t been much good news out of publishing and media since the Great Recession, but one segment, recorded audio, is exploding everywhere, all at once. The US audiobook market recored 47 per cent year on year growth in the last twelve months. Audible Australia recently announced an aggressive push into the local market. And audiobooks’ precocious sibling, podcasting has turned from a fringe media curiosity into a battleground between streaming media giants like Google, Apple and Spotify.

The big players are spending hundreds of millions of dollars acquiring smaller podcast networks and tech start ups, or making content plays like Audible’s global push to secure exclusive rights to recoded books before traditional publishers can lock up the IP.

Audible’s play is fascinating and—full disclosure time—I’ve seen it from the inside. A couple of months ago the company approached me and about a dozen other local authors wanting to buy up the rights to a range of titles across genres and subject areas that the company’s data mavens already knew to be hot sellers. Partly the move hedged against a perceived push by rival and frenemy Apple into the audiobook market. (A huge number of audiobooks reach our ears via iPhones and Apple has recently begun to ramp up its own audiobook offerings). But Audible may also have been looking to counter the slower, creakier but inexorable turning of the Big Five global book publishers towards the only real growth sector in their industry.

Until recently, audio was a minor consideration for the likes of Random House or Macmillan. Now the big houses insist on bundling the audio-rights into their author contracts, usually without additional compensation. Audible’s business works in the opposite direction. They secure exclusive recorded media rights and the option to produce the content in other formats if sales are good.

The link between audiobook growth and the podcast industry is close. According to stats released at the London Book Fair in early March, and reported by publishing newsletter The Hot Sheet, “Podcast listeners listen to twice as many audiobooks as non–podcast listeners. People move back and forth between podcasts and audiobooks—they are gateway drugs to each other.”

They can be also huge, flashing data-points for digital marketers and online retailers such as Amazon, which owns Audible. The fastest growing segment of the audiobook industry is non fiction, and the iTunes podcast directory, the largest in the world, is effectively a library of collected micro-demographics.

For a music streamer like Spotify, podcasts offer relief from the licensing fees they have to pay music companies every time a subscriber rolls a tune. For Google, the advertising and search behemoth, audio content provides yet another rich source of exploitable information about the preferences of users, and an intimate channel directly into a listener’s head, along which targeted advertising can be sent.

Just as Apple is moving into TV content to lock consumers deeper into Cupertino’s ecosystem, Audible’s exclusive content play and the frenetic deal making in and around the podcasting industry, can all be seen as power moves by the tech giants to both control and exploit an emergent form of media, each for their own strategic ends.