Spotify "Free" Question- Stops playing after a few hours or less??

[Beccaflowers7]

With the latest few Spotify updates- I noticed yesterday while playing my music after a period of time, not using my computer, which to mention, when I listen to my Spotify, its used more of a stereo than a computer.  Spotify stopped working with a message in reference to, somethings like this. "Do to your computer not being used in a period if time we stopped Spotify.  Please restart."  WTH is that?  It also mentioned something, if you don't want this to occur/stop playing- try Spotify premium?  This is unbelievable and unfair.  Just a bad way to force people to buy Spotify premium.  No No No!!  I play my Spotify and walk away.  Now I have to turn back-on after a few hours or less.  What a pain.  Again, its all about the mighty buck.