The best part is that no fees are charged, which I still do not get. Don't you have to pay transaction fees at the very least, but yet no fees are charged? I know people can choose to donate, but how much I am not sure how much.
I assume this must be a part of early days promotional offer. I read chipmixer accepting donations instead of mandatory fees for providing mixing services. It means we can pay the amount what ever we may prefer as fees. A generous user may finish of his mixing services along with splitting once chip with 0.001 value for donating to chipmixer at a same time a bitcoin whale may prefer donating 0.1 bitcoins too.
That's exactly what is applicable here and I think its something that tries to appeal to our own personal feeling to give based on the services have received rather being other mandatory obligation to make such payment and this is what chipmixer is bring to the space. A service that is more client oriented rather than the owner or administration or the site.