I'm sure many of you are already trying this. But for those who don't know, arbitrage in cryptocurrency just means buying coins from 1 exchange at a lower cost and selling on another exchange at a higher price.
I believe software is being created so you will be alerted via your phone(app) telling you when there's a coin that has more than 3% difference in price between exchange so you can safely profit after all the fees.
You might also find this video useful:
Credit
Buy and sell digital currency using 'Coinbase' earn $10 when you sign up