A number of years ago, I heard it said that if you had a self-made millionaire and you took away all his money, before long he'd be rich again, because he knows how to make money, that is, because he already has the hard-earned experience in what it takes to bring himself an income from various legit directions even if he has to get out there and bust his butt again.
Now, I look at Virwox. They WERE second *only* to LL's own L$ exchange, Lindex, in amount of L$ bought and sold through them. As has been pointed out multiple times here and on the other blog posts talking about the surprise TOS change.... they made $38 million in L$ trades last year. They're like that proverbial millionaire who just had it all taken away from them, except in this case they still have whatever remaining profits they had in the bank from recent times. Guess what, they got to be the 2nd biggest L$ trader in SL by their *own* *hard* *work*, I strongly expect they'll get to be the biggest trader in other virtual-world currencies *also* by their own hard work, probably quite soon, since they already have the hard-earned experience at doing so in SL with L$.
At least some of the other exchanges can be looked at in a similar light, but I bring up Virwox in particular because they were the top of the heap.