...And that's why the exchangers are having very, very low fees of 0.2% for trading or free for withdrawals. They do not care about these money. The REAL money are made with the Bitcoin price. How can financial company exists with 0.2% per transaction?
Super tight spreads aren't uncommon in forex trading where fierce competition between retail FX participants is the norm. Also, compared to traditional financial companies, overall transaction costs are probably lower as it only costs a couple of cents to send/receive any amount of BTC to/from anywhere in the world in minutes. So with the lower fees, lower overhead costs, and lack of middlemen, I think it would be possible for an exchange to make a profit by just trading and withdrawal fees alone.
Even when Mt. Gox had 800,000 BTC (worth almost $1 billion in late 2013), it was still a pretty small-sized company. Their expenses probably weren't that much compared to more traditional financial companies that deal with similar amounts of money. Scottrade has 4,000 employees and GAIN has about 400. A Bitcoin exchange would have, what? 5? 10? Maybe 20 tops?
The forex market is HUGE. A LOT of people are playing in it(including BIG banks). You cannot compare Bitcoin market with 1 MIL users with the forex market.
MT Gox had ONE full time employee and 3-4 part time contractors(for customer support-tickets). Try to not believe everything these guys are trying to show "you". They are small companies not corporations.
It's not something bad to be a small company. It's absolutely normal to have a small and cosy office when you run an exchanger... but these people wants bling-bling. They want to be like Trump or Zuckerberg overnight
The bad thing is when you want to be what they are not...
You said "Mt. Gox had 800,000 BTC (worth almost $1 billion)". Let's say you have this Bitcoin. Who is will give you the money if you would have 1 billion worth of Bitcoin? Coinbase? Bitstamp, BTC-China?
Yes, nobody. because they do not have these money. But if you want to withdraw a billion from a real forex company, you will get it ASAP.