Chipmixer source of income is the fee only which they get from their users while cryptotalk has the whole Yobit exchange with them for funding.
The most incredible is that they charge no fees. They live on donations.
https://chipmixer.com/faqWhat fee do you take?
We use Pay what you want as pricing strategy. It mean you set how much value our service is to you.
You may split chips into size you wish to donate.