I think that the US airstrike will decrease ISIS' power for a short period of time. However, I also feel that they have money elsewhere. ISIS is a powerful group and they will always find people to fund their misguided behavior. But,I feel that the airstrike was a step in the right direction.
While there is a danger that U.S. airstrikes will help ISIS recruit new members due to increased hatred of western ways, they are a well-funded group and we must do everything we can to decrease their power. Loss of military items and places to congregate and plan or recruit can only help in this fight.
While attacking the primary means of financing military and para-military options makes sense on some level, the mid-east is so awash in cash, and the list of haters of the United States is too long, for such sporadic strikes to have any real effect. So, a temporary setback is all that should be reasonable expected.
Targeting and destroying ISIS' ways of making money will not defeat them. What it will do is cause them to retaliate because they will need to take extreme measures to keep their money flow coming. The one and only way we are going to defeat ISIS is by finding their leaders and absolutely destroying them so that even their followers are so demoralized they will not keep performing acts of terrorism.