As Spotify pitches its coming public listing to investors, there are signs the music streaming service is holding its own against Apple Music. But Spotify still is wrestling with how to improve its weak margins and work toward profitability.

Apple Music’s sales growth is decelerating in the U.S., according to a sales analytics firm. Although Apple remains a fierce rival, investors and industry experts don’t believe it will cut significantly into Spotify’s growth, because of the broader shift of music sales to streaming.