I can't decide if you're making a sarcastic statement about money appearing to make one happy, or actually portraying the feeling of happiness equalling money. The choice of green and the title plus that being the obvious would indicate the former, but the fact that the notes look so cute imprints in my mind: money! happy! So I guess even if you are making a statement against "the insidious nature of the way we think about money", your design can't help but persuade in the same way as advertisements, by combining something to sell with a feel-good image; whether you mean to have this effect or not.
Um, I have no idea if any of what I have said makes sense. Please tell me what you were thinking when you designed this, as I am interested :)
About my design