multiple users

[raulmagjr]

Why can't we play music with multiple devises at the same time using the same account...it normally stops one of them so that only one could pay

[Nullgrad]

This could be included as part of Spotify Premium but I doubt if it would be allowed under Spotify Free, something along these lines works on Sky's Now TV you can register upto 4 devices and watch on 2 of them at the same time.

[Peter__]

That is correct behaviour, and it all comes down to licensing. 

Spotify is licensed for personal usage only, so each person should have their own account. Since you can't be in two places at once, Spotify (in line with their agreements I would imagine) restrict you to only being able to have one stream open at any given time to prevent account sharing.