I was just wondering how this business model can stay afloat with the massive costs involved. Darkstar recently returned from his vacation and I noticed the pay out for the two weeks posting spree would have cost Chipmixer more than 2 bitcoins. Nearly $10k for 14 days which is a massive overhead cost. Given that you don't charge fees, I can imagine the signature campaign eating heavily into profits aka donations from generous users of the mixer.
I hope your customers will donate a more generous portion of their mixed coins. I would suggest introducing a fee system similar to bitmixer's traditional pricing model in addition to an option to donate.
Probably some of the revenue came from the dice option of the site. I, for example sometimes play there and lose some BTC Though sometimes I win but there is more occasion that I lost on the bet. Though I favor that it is in the best interest of the company to charge for the service. There is no free stuff in this world