Okay, my bad; I tought that you added the coins before pressing the button so that private keys only needed to be pressed once. Mixing the coins I've seen this other promotion, but I have a couple of doubts about it;
If you satisfied using Sudoku Wallet, please leave your mention on Bitcointalk thread.
Indicate last 5 symbols of your wallet key in your post, and we return all mixing fees to it's deposit address!
What is the point of sending the coins to the depositing address if it's no longer private? (since it's been used both to receive and to mix) It's a bit counter-anonimity if you asked me....
For the other promotion, the one you've announced here, do you send the coins to the depositing address too? because that is rather misleading and can be a problem in the case of people mixing coins coming from exchanges or other platforms that use different deposit and withdraw addresses