Snap chat was a gimmick: A message/photo/video lasts for a short time and then goes away. That started to loose steam so they went down the route of becoming more like a traditional social network. As the lines blurred between Facebook and Snapchat people decided to start going back to what worked and from Snapchat for the top down. Then the new gimmick networks start getting popular eating away at Snapchat's popularity from the bottom up.

Snapchat is getting eaten away from both ends. And teh bad PR is just next steps.

Snapchat has to do a vertical move. Maybe get into the through-away camera (not the expensive on they tried), cheap Android devices like what TracFone does for quick snaps on the go, or make a partnership with Urbanspoon/Yelp and do a go branded marketing campaign for the best snap with friends.