The latest trend in podcasts? Making them into movies

The main difference between when Matt Lieber cofounded Gimlet Media three years ago and now? Now, there's actually a business model.

He's not joking.

"When we first started [Gimlet], the company was an idea," Lieber said. "When we raised a Series A, the company was a halfway-working business model, and now that company in a Series B has a working business model."

On Wednesday Gimlet Media announced its second major round of investment — a $15 million Series B from a group of investors including Strips Group and Emerson Collective, the organization led by Laurene Powell Jobs (who recently bought a majority stake in The Atlantic).

In just a few years, Gimlet has put together a lineup of podcasts — including "Reply All," "Homecoming," and "Crimetown" — that rivals the offerings of incumbents like NPR and Slate.

Gimlet's rise mirrors the broader growth of the podcast market in the past few years from a few big names to a rich (and impressively diverse) field of podcasters.

The thing that changed is advertising.

"The medium is maturing and part of that is being discovered by new advertisers, part of that is giving advertisers the level of comfort they get through analytics that our audiences are real and measured and we're delivering a very reliable and safe product," Lieber said.

However, that's not necessarily what brings in major investors with millions of dollars. Podcasts are good, sure, but movies and TV are better. That's why Gimlet's already got a few big projects in the pipeline, including "Alex, Inc." starring Zach Braff. It's an ABC series based on the experiences of Gimlet cofounder Alex Blumberg with his podcast "StartUp," which helped launch Gimlet.

The idea is to have Gimlet's podcasts serve as a way of gathering stories that could work as bigger projects. For example, "Man of the People," starring Robert Downey Jr., and directed by Richard Linklater, is based off a "Reply All" episode about a doctor that scammed his way to fame. "Homecoming," based on Gimlet's first fictional podcast, will star Julia Roberts.

Those big names have helped put Gimlet on the map, an important step for the company as it grows.

"It's hard to separate our success in TV and movies from our success in the world, because one of the things that happens when you make a show with a caliber of talent ... it creates a level of awareness and it just builds Gimlet's profile in the world," Lieber said. "So I think it is a meaningful part of the business, but it's also about building the Gimlet brand."