If money is kept in margin account maintained with the broker, you do not earn anything on that money. (passivefunds.in)
I have a number of margin accounts with various brokerages but that's just because it's the setup that fits my goals and risk profile the best. (thecollegeinvestor.com)
That said, the broker is built solely for professional traders and requires a $ 100,000 minimum deposit for margin accounts. (stockbrokers.com)