Nearly 80% of respondents who used both Spotify and Pandora said they were replacing time on Pandora with Spotify, and further results did find that average weekly time spent listening to Pandora had fallen. For example, US internet users were most likely to listen to Pandora for less than 1 hour a week, cited by 47% of respondents in November 2014, vs. 39% in December 2013. All higher frequencies fell or remained the same.
Still, eMarketer estimates that US adults spent more time daily with Pandora than all other digital radio in 2014, at 25 minutes vs. 14 minutes. Read the rest at eMarketer.