From what I can say regarding CS conferences, ACM just rubberstamps and pockets the money. At one recent conference, the organizer addressed the concerns about

From what I can say regarding CS conferences, ACM just rubberstamps and pockets the money. At one recent conference, the organizer addressed the concerns about high fees saying something like "well, most of it went to ACM, so we may hypothetically save on that, but we understand that the bulk of participants come from academia and they need the proceedings". Meanwhile, the "proceedings" are purely virtual, the same PDFs we submitted put online at ACM Digital Library. Bloodsuckers.