User blog comment:A.J AL/Season six plot hole./@comment-24169020-20121215024922/@comment-3045936-20121216181124

True million to billon is a big number difference. However, Crowley knew that Castiel was depresent and figure with a revived Angel and all the knowledge of Heaven that Castiel could get. They could fnd that souls of Purgatory and use them. After all, who is to say that Crowley can affectvely use the near to 7 billion souls that were already there. New souls might be more useable. But that is a plothole too.