Back in the day, business travelers used physical airline tickets. This helped, though did not ensure, that when non-refundable tickets went unused, credits would be applied to other trips. Then tickets went electronic, and they were more often forgotten. Managing unused ticket credits remains a pain in the a$$. And that's company cash. So when an employee leaves the firm, one buyer suggested, taking airline credits with them is tantamount to theft.
Even short of that, the numbers aren't inconsequential. "Mid-to . . .