They used a repetitive song that they probably don't even have the rights to so they could use it in GD.
Very nice remix :)
This is a really good song nice job.
Epic only word that comes to mind
Really... Best. Avicii. Remix. Ever!
Dubstep in Avicii... That Something you should hear!
Please contact me if you would like to use this in a project. We can discuss the details.