JUSTIN BIEBER Cancels Concert Because of Empty Seats

Justin Bieber cancelled his Portugal concert Tuesday -- not because he's sick, not because he's melting down -- because ticket sales were "soft" and it felt like the right thing to do. Just tell that to the fans who are getting stood up.

Bieber's Star

•  Shining
•  Fading

Sources connected to Justin have confirmed ... it was a "business decision" that triggered the cancellation. Our sources say ticket sales were still "good ... more than 60%" ... just not good enough.

It's pretty common for lesser artists to bail when sales are bad, but unusual for singers on Justin's level.

SOURCE @ TMZ: