"I thought you meant people using Bitcoin to do arbitage between (old school) currencies X and Y" That's precisely what I suspect (and can only guess at this p

"I thought you meant people using Bitcoin to do arbitage between (old school) currencies X and Y" That's precisely what I suspect (and can only guess at this point) that it is being used for: http://bitcoinmagazine.com/btc-trader-bitcoin-arbitrage-made-easy/ http://bitcoinmagazine.com/btc-trader-bitcoin-arbitrage-made... http://lichtman.ca/is-bitcoin-arbitrage-feasible/ http://lichtman.ca/is-bitcoin-arbitrage-feasible/ https://github.com/michaelcdillon/BitCoin-Arbitrage https://github.com/michaelcdillon/BitCoin-Arbitrage At the same time, MtGox also serves as an entrypoint for non-speculating users and has effectively become the "Bitcoin bank." It's voluntary - people are choosing to use MtGox, but in this regard MtGox's success seems to be a Bitcoiner's weakness: a DDoS against MtGox can cut the value of a BTC (and their lunch money) in half.