Payment up front is something we (Cro 2) insist on when running any sort of campaign or competition on forum. We don't work with companies that aren't serius and feel like few months worth of escrowed funds are necessary to show commitment and atrract good members.
Better to always go for an upfront payment incase of uncertainties like this should occur, they may even be the ones loosing instead of putting their campaign participants on a dashed hope on nothing, but there's a level of how one could have built a rapport with these same employers/organizations without them paying up front and then you trust their reputation and representative as well, but in this case, it's risky to take and those managers that engage doing such already have their own personal money as backup in case of uncertainties.
Anyway realy unfortunate situation but sort of expected, a lot of mixers rushed to fill CM void and while some are trying to make money trough quality of their service it was inevitable that some would simply scam their way to profits.
You're right, after the incident with the CM, there's a notice on sudden boom on how these mixers were appearing and operating, yet i want to believe most of them have been this good intentions to make a good reputation in quality service delivery for their users.