Whereas paying it forward in drive-throughs occurred maybe once or twice a year a decade ago, now fast-food operators said it might happen several times a day.
“This is an example of goodness gone viral,” said Ms. Ryan, who since the publication of “Pay It Forward” has become somewhat of a clearinghouse for random acts of kindness. “People bring me their pay-it-forward stories, and I’ve been hearing about the drive-through phenomenon a lot lately.”
Perhaps the largest outbreak of drive-through generosity occurred last December at a Tim Hortons in Winnipeg, Manitoba, when 228 consecutive cars paid it forward. A string of 67 cars paid it forward in April at a Chick-fil-A in Houston. And then a Heav’nly Donuts location in Amesbury, Mass., had a good-will train of 55 cars last July.