Did they intend to be clever?  Did they intend to shock?  Did they just want to get noticed?  Maybe all three.  The story did get them some free national publicity, but I'm not sure this is the publicity that you really want for your restaurant. 

Personally, it might be difficult for me to enjoy their "kool aid" after hearing about this whole story.  The billboard referenced the Jonestown Massacre that claimed the lives of  more than 900 people.  Not quite sure who they were trying to reach.  Younger people wouldn't get the reference.  Older people would be offended by it.  It was a Lose/Lose from the start!  So, my guess is they did it for just this reason, so people would talk about them.  Problem is they're talking about the billboard now and not the restaurant.  

The restaurant company said was looking for a way to say they want their customers to have that cult like love of their establishment.  If that's the case they should have referenced Justin Bieber fans or Lady GaGa fans and put a positive spin on it.