'I understand sending money the first time, but how do you still fall for it the 6th time they ask you to send more money?'. I think that falls under the "sunk

'I understand sending money the first time, but how do you still fall for it the 6th time they ask you to send more money?'. I think that falls under the "sunk cost fallacy". Like they are thinking "Well, I've invested so much money already and I'm so close to the payoff now, I may as well send a little more"