Avicii Says he hasn't sold out in interview here:

In the interview, Avicii says he hasn't sold out.  Take a listen and see what he has to say.

He definitely has stuck to producing the same sound but EDMBostons asks why??  Armin van Buuren always says "don't be a prisoner of your own style" and we can't help but think Avicii is the definitive artist thats stuck. At this point it will be very challenging from him to switch out of his pop progressive sound and have a long term career.  Ash has set him up to follow the same trajectory of the hip-hop stars of yesteryear and its pretty sad.

Avicii is a talented producer and you have to give him credit for levels no matter how sick of it (and we're sick of it) you are.  But where is he going with it all besides commercial success?