It is an awkward notation. Nobody says 100M for $100,000, they say 100K. So why should 100 million be 100MM? It forces people to pause, and think unnecessarily.
Only if by Nobody you mean every person in the oil & gas industry. I find it funny that people get so worked up about different units in different industries. I get that common units would be great for a variety of reasons, but look around - the world can’t even unite on standard units for such tangible things as distance/length. People who work with MM as million are familiar with the vernacular, and it seems unreasonable for them to upend a model that works so a lay audience doesn’t have to pause and think.
I've been in the oil & gas industry for 20 years (IT side of things). We never use MM, I'm looking at last years half year results, and it's "m" across the board.
I'm the opposite. If I see "10M" in financial docs, then I have to pause think about context. If I see "10MM" I'm certain that the author meant "million" and keep on reading.
