It may be comfortable for Monika to write a check for a month of massages from her checking account, but she'd probably squirm at the notion of spending any of her inheritance on the same spa treatments. In this context, couples who set up a savings account purely for travel do more than move $100 from one account to the other. They are actually changing the nature of that cash.
It becomes, perhaps, more sacrosanct—much harder to blow on other things—and more shared. Now, spending that $100 on a nice lunch might not only be a violation of their savings plan, but also a belittling of their vacation time and, consequently—at the deepest level—of their commitment.
Personally, my partner and I aren't ones for a lot of buckets—which may be just as well. CPA Steve Deutsch in San Francisco points out that consumers can be easily fooled by hidden "convenience" fees and penalties when they sign up for multiple accounts. "How do you think the banks are making so much money?" he asks. "They're not doing extra paper work for nothing."
But when Tricia's husband puts money aside for each of his children, he's caretaking. Logically, there's no difference between a lump deposit of $400 and the separate $100 deposits he makes in each credit union account. But internally, for whoever is listening, he's saying something pretty profound about family.
Ultimately, though, the really sensitive banking area is not the number of accounts. It's the decisions that involve sharing. No choice at the teller's window is as freighted as the one about joint versus individual accounts.