The 5 plays doesn't appear to renew at the end of the month like the number of hours, and it just means that my playlists have more and more holes in them (as often has happened when artists suddenly change their minds over streaming). Spotify tried to explain that most of their users only use their service to discover new music – maybe I'm too hipster for them, but the new and interesting music I want to listen to isn't generally in their catalogue, and last.fm's discovery features are much better.
When they provided everyone free access for unlimited plays (with ads, granted), most of my friends used it and updated their playlists — which I would subscribe to and we'd drop music on to each other's user icons and share interesting music. Now, even if I were to re-upgrade to premium (which I probably won't, especially when in the UK we appear to be getting a raw deal in cost), it's like a ghost town.