Shares of online radio service Pandora (NYSE:P) were on the rise today. The subscriber numbers are beginning to increase as the company is reaching out to more in-car listeners. With 2.5 million members listening in cars, Pandora is now available in 100 car models. And yet, more artists are speaking out against Pandora's attempts to cut royalty fees. In this installment of Stock of the Day, Motley Fool analyst Matt Argersinger discusses Pandora's new subscribers, the long-term challenges facing the business, and whether investors should look into shares.

Chris Hill and Fool contributor Matthew Argersinger have no position in any stocks mentioned. The Motley Fool recommends Pandora Media. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.