Is hearing back in less than a week bad?

[M3d3a]

I submitted both of my applications last Friday (1/30/15). About an hour ago, I received an email stating that I had been accepted for an interview from a Professor in the program. While I am excited, the quick turn around time has me worried.... Is it possible that the program is extremely desperate? Or am I really that desirable? 

[Eigen]

Please don't double post the same topic.