Which makes you part of Pandora's claim that they're the most used mobile app. Leaving a desktop computer streaming music on at work has nothing to do with mobile app usage.
It illustrates that music apps are likely to be in use for very long periods/proportions of time. maccard's comment was quite relevant; it's not at all unreasonable to read in "and other people might use pandora similarly to the way I use spotify".
It's obvious that music apps get used for a long period of time. That's why Pandora is one of the (if not the most like they claim) most used mobile apps in the world. Leaving Spotify on at work while you aren't there is not the reason why.