Yes I know, your least-favorite idea goes here. But seriously, someone must have come up with the concept before. Like a bad get-rich-quick scheme could fall into this category, where joining the scheme makes people lose money and become more desperate, so they become more likely to do desperate things like invest more in the scheme. But it can apply to a number of other bad ideas.
Sunk cost fallacy is probably the most obvious one that springs to mind. Not unlike gambling in a sense, people feel they just need one big payout to win it all back and then some, so they keep betting, hoping that this time things will go in their favour.