Don't you have a reserve of your own to provide bitcoins or is it simply using new customers bitcoins to pay for old customers?
If you read back a page or three, you'll see that they're considering various solutions to the "out of chips" issue... currently, it would appear that their setup doesn't scale well... and since the demise of bitmixer, they've become VERY popular... so, in a way, they've become victims of their own success.
I'm personally hoping for an investment option to increase the bitcoin pool... I'm always on the lookup for ways to make my bitcoins earn their keep

I understand this but it just seem to me very weird that a mixing service will run our of coins... I mean you just mix the coin and re use them for other people no? If it is so successful he should never run out of coins.
The more people that use your service the more coins (fees) you make and you can provide a stronger anonymity to your clients.