Online exchanges of money among friends and family are a great convenience. But users face a hidden risk: Paying someone exactly what you owe them could damage your relationship.
Back in the 20th century, if you paid for a shared meal that cost $20.04, your friend technically owed you $10.02. Rather than force your friend to fish around for two pennies, however, you might have been happy to accept a $10 bill and “call it even.”
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