I more meant anyone on Facebook who listens to a track streamed from Spotify while on Facebook and not having even been to Spotify's site or having downloaded a

I more meant anyone on Facebook who listens to a track streamed from Spotify while on Facebook and not having even been to Spotify's site or having downloaded any client, could be called a "user". 50 million people finally seeing real music integration on Facebook listening to a track or two doesn't seem unrealistic, but if that's what they call a user, they're being very generous to themselves.