You don't need to buy or sell from just other Coinbase users. It can be anyone. Coinbase doesn't have a huge market share yet, so it's even less likely. I thin

You don't need to buy or sell from just other Coinbase users. It can be anyone. Coinbase doesn't have a huge market share yet, so it's even less likely. I think a fair way to read it is that $1M worth of transactions occurred of which Coinbase made some money.