Pandora (P) shares rallied 5% Wednesday after the music streaming company said it logged gains in listener hours and market share in September.

The stock jumped to $26.82 in early morning trading, adding to Pandora’s 178% gain as of Tuesday’s close.

Listener hours climbed to 1.36 billion last month, an 18% gain compared to September 2012. Pandora’s share of total U.S. radio listening widened to 7.77% from 6.53%.

The company reported 72.7 million active listeners, up 25%.

On the flip side, gains in listener hours indicate a continued increase in royalty costs. Pandora has reported higher losses in recent quarters, as significant listener growth has pushed royalties higher.

Pandora purchased a small South Dakota radio station in June, looking to make the company eligible for lower music royalties.

Last month, the Internet radio company named Microsoft (MSFT) veteran Brian McAndrews its new chief executive and chairman, ending a six-month search.

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