Pandora now offers on-demand streaming as a subscription service (Pandora Premium), just like Spotify. This has been available since 2017, after Pandora acquired the assets of Rdio.[1]
Pandora's music discovery features are best-in-class, but its maximum audio quality is lower than that of other services (192kbps vs. Spotify's 320kbps).[2] Pandora also pays artists less per stream than Spotify and most other services do,[3] probably because Pandora has a huge proportion of free users.
Combining Pandora's superior discovery functionality with Spotify's ease-of-use and control would be great.