Spotify said on Tuesday that it had agreed to buy Parcast, a podcast producer known for crime and mystery series, as the streaming service continues its quest to become the biggest home of online audio.

The deal for Parcast, whose 18 shows include “Serial Killers” and the fictional series “Mind’s Eye,” comes several weeks after Spotify agreed to buy two other podcast companies: Gimlet Media, a podcast studio, and Anchor, a podcast tool maker.

All three acquisitions highlight Spotify’s main goal: offering not just music, but essentially any content that users would want to listen to. By snapping up podcast producers, the streaming service is hoping to stock up on high-profile titles in its rivalry with Apple, which has historically been the top podcasting platform.

Podcasts help Spotify in other ways as well. They are relatively cheap to produce, in that way improving the company’s profit margins, and help reduce the service’s reliance on expensive music licensing rights. And popular podcasts can attract a faithful audience of subscribers.