[mattinglot]

I think this is brilliant too. It's another way to save money that would otherwise just disappear without you retaining any noticeable value from it. I would definitely use it if it were available to me, but on top of the 10% savings not instead of.

As for advantages over other methods, beyond the obvious forced-savings: I see this as the creation of a self-imposed "spending tax" that discriminates against small "insignificant" purchases that add up overtime (53 cents change is a relatively big percentage of 5 dollars, but not of $50), helping to perhaps dampen the effect on the wallet from the unnecessary little purchases like fancy coffee drinks and eating out too much that most of us make.