The price difference between gox and stamp.
By my calculations every $1000 invested gains roughly $67 when converted to btc on stamp and back again on gox. If you live in the sepa zone, is this really not worth doing?
Why is everyone not doing this?
This is one of the easiest ways to make money in existence. (Provided you already have some).
Thoughts?
You would earn more if you just play the market on bitstamp, sell for high and buy for low, but calculate fee and there you go. If you have no life and enough time to spend you can earn a lot.