CPM considered harmful

I work in online advertising. Those little ads tend to be sold in CPM. What does CPM mean, you ask? Well... since the advertising industry consists of Ad Men (think used car salesmen, but with a better suit and more cocaine / meth), there are no less than 4 possible interpretations of this fine acronym. We have: "Cents Per Mille", "Cost Per Mille", "Cents Per Million" and "Cost Per Million". I mean, it's not really that important, since it only relates to billing... Oh wait. Yes, the online ad industry really is that fragmented and yes, they're really too stupid to agree on a single interpretation of a critical unit of measure, let alone just picking a completely clear metric unit.