If you grant that the income is solely through some 0.001 BTC amount per transfer, then you come to a figure of (assuming ~US$55K/BTC) about 1800 transactions per month, averaging 60 a day.
You right "about 1800 transactions per month" in this case.
So, if only 0.01 BTC in each transaction then only 18 BTC or ~ $1 000 000 per month go throw the CM. Indeed, modestly ))