Tina Jensen, general manager of the Dairy Queen in Brainerd, told ABC affiliate KTRK it’s not unheard of for customers to pay for what the person behind them ordered as a random act of kindness.

When that happens, employees will typically ask the customer whose order was paid for if they want to do the same, and at most, the chain will stretch for 15 to 20 cars before it breaks.

But on the afternoon of Thursday, Dec. 3, a customer sparked a chain that would take more than 900 customers all the way through Saturday night.

Jensen told NBC affiliate KARE that the recipient of the first act of kindness was surprised to learn that the man in front of her had paid for her order.

‘She’s like, “Really? Why would he do that?”’ she recalled. “I said, “We just have it every once in a while where someone will take care of the person behind them, and today is your lucky day.”’”