Music-streaming service Pandora is buying AdsWizz, a company that simplifies buying digital audio ads for marketers, in a $145 million cash-and-stock deal.

Pandora lately has focused on video advertising and premium subscriptions to make money and better compete with rivals like Spotify and Apple Music, but audio ads have been Pandora's go-to revenue model for years. Earlier this year, Pandora indicated that moves -- like this AdsWizz buy -- could be in the offing when it said it would lay off about 5 percent of its staff in January to free up money for investment in items like advertising technology.

"Since I joined Pandora six months ago, I have highlighted ad tech as a key area of investment for us," Pandora CEO Roger Lynch said Wednesday in a statement. "With our scale in audio advertising and AdsWizz's tech expertise, we will create the largest digital audio advertising ecosystem."

Pandora said in the statement that the addition of AdsWizz will upgrade Pandora's ad-tech capabilities, give Pandora advertisers greater audience reach and widen the company's revenue opportunities. AdsWizz is one of the few ad-tech firms completely dedicated to digital audio.

The takeover means advertisers will be able to do business through AdsWizz's marketplace on Pandora as well as on other audio publishers. Pandora said it will support AdsWizz's core business that serves all people involved in its ad marketplace, not just Pandora.

Pandora agreed to pay $145 million in a combination of cash and stock. At least 50 percent will be a cash payment; the rest will be either cash or stock, depending on Pandora's preference. The deal is expected to close in the second quarter, subject to closing conditions and regulatory approval.

The Smartest Stuff: Innovators are thinking up new ways to make you, and the things around you, smarter.

Apple: See what's up with the tech giant as it readies new iPhones and more.