What just happened? After conquering streaming music and shaking up the podcasting scene, Spotify is turning its attention to audiobooks. On Tuesday, the Swedish audio behemoth announced that listeners in the US can now purchase and listen to more than 300,000 titles. Audiobooks are launching with a new user interface geared specifically for the medium that was designed to sit alongside music and podcasts without making the platform feel crowded.

Books will show up in search and curated recommendations with a lock icon on the play button meaning they need to be bought in order to listen to.

Purchased titles will be saved in your library and available to listen to at your leisure. Books can also be downloaded for offline listening, and the bookmarking feature will automatically save your place so you can pick up where you left off. Spotify has additionally baked in a variety of playback options to speed up or slow down the pace, and a rating system will allow you to share your opinion after listening to a book.

Spotify is positioning audiobooks as a separate division, meaning there is no discount for premium (paying) subscribers - at least, not at launch. That varies from rivals like Amazon which offer Audible perks for Prime subscribers.

Nir Zicherman, Spotify VP and head of audiobooks and gated content, acknowledged that audiobooks represent no more than a seven percent share of the wider book market. That said, the category is growing by 20 percent year over year so there's certainly potential in the venture.

Zicherman said they are especially excited about introducing audiobooks to an audience who may never have tried them otherwise. And really, that's probably their biggest opportunity for growth. Not offering a discount to premium subscribers feels like a mistake, and I'd be willing to bet Spotify could land more newcomers if they offered a free book to let users try out the service.

Spotify will use the knowledge it gains from the US debut to help plan for launches in additional markets and guide new feature rollouts.