$10 on $100 is far more than their fee. If you signed up, bought on Coinbase and sold on GDAX at the same price you'd make $8.51. Small but indeed free money if

$10 on $100 is far more than their fee. If you signed up, bought on Coinbase and sold on GDAX at the same price you'd make $8.51. Small but indeed free money if you know what you're doing.