unfortunately they send with mixing 0, rest worked fine for me. sometimes the price they offer is not so good, sometimes its better than on the exchange.
Hmm, I haven't tried it myself, but I could've sworn that I read Shapeshift uses mixin 3 now. I thought it was on reddit, but not seeing it now. Did you try within the last week or two, or longer ago than that?
They set it back to zero because of some problems with dust outputs or something. I don't know who received that message, but if you read this, please come and elaborate more on this matter (or perhaps shapeshift itself could elaborate?).
Just fyi,
I just tried shapeshift, (I just can't say no to +500 xmr/btc) - the transaction was done with mixin = 1
Looks completely obfuscated to me, but I'm really only starting to experiment with Monero transactions.
I just looked through my IRC log, and I'm not entirely sure, but it looks like the lowered mixins have to do with too many support tickets cropping up because the wallet software gets messed up with random huge transactions due to "not enough outputs to mix". So, my interpretation is that for personal use, you could fix this kind of error just by retrying with different send amounts etc, but with an automated system (like shapeshift) it doesn't work as well.
In general, I think this phenomenon is on the to do list, wherein the codebase will be modified such that any output can be utilized for a ring signature, as opposed to just unspent outputs. This has the effect of increasing the total number of available outputs for inclusion in the ring signature. This was in one of our podcasts somewhere.
You can't stricly enforce 1), people can make mistakes, or they can decide to "bloat" your wallet maliciously.
Edit: Note that the two hot wallets could send with mixin of 1 for consolidation. Only user withdraws have to be 3+.