The problem is that the arbitrage possibilities using the exchanges he quotes involve making transfers in fiat for repeated buy/sells. The ~2% arbitrage he quoted cannot be performed on all funds on a daily basis, it would be spread out over several days. It's not possible to provide the returns he posted on btc-arbs unless he is using other mechanisms than the btc-e/bitstamp arbitrage route, such as a ponzi. At the moment, I think the easiest money to make is to hold a short position in dogecoin.