It's common sense that if you cut off money to a group you are fighting, you have a better chance of winning. The North won the Civil War in part because they cut off supply lines and commerce to the South, who then could not fund their efforts. The same would work in this situation.
In general, I'm against war, but to hear that they are cutting funding the war makes me jump out of my shoes in excitement. We shouldn't be fighting, especially over causes that are stupid and didn't have have a reason to start. That is literally all that I have to say.
I'm glad to hear that ISIS is cutting the salaries of fighters, that way many of them might stop fighting all together, and the higher command will then realize that most of those fighters only do it for the money, and not because they believe in the nonsense. ISIS' (aka Daesh) enemies should just keep fighting them at full power, and not cut any funding.
I think the countries fighting Isis or Daesh should put more emphasis on it if they see that the other side is weakening. They have to eliminate this terrible curse on humanity by this sect using a real religion to piggyback hate and violence in their mentality leading to indoctrinated societies.