Story highlights Six times this week, donors buy coffee for more than 500

Gifts were at Tim Hortons restaurants across Canada

Chain says this generosity is not a marketing gimmick

What's in the coffee in Canada? Apparently something that's making a few folks pretty generous.

At least six times this week, customers at Tim Hortons restaurants have paid for their own cups of coffee and cups of brew for the next 500 or more people in line, according to media reports.

The first 500 free javas were gifts of an anonymous donor at a Tim Hortons in downtown Edmonton, Alberta, on Monday, CTV reported . A man in his 20s bought a double-double and a doughnut and told the clerk to put the next 500 large coffees on his debit card, according to the report.

"(The staff was) thinking maybe he was so blessed that he wanted to share his blessing, or maybe he won the lotto or something," store manager Joanne Averion told CTV.

The act has been repeated five times since, in Calgary, Alberta, on Tuesday, and in Red Deer, Alberta, and Ottawa on Thursday, and two more times again in Edmonton on Thursday, according to the Canadian Broadcasting Corp.

The last case is the only one where the coffee donor has taken credit.

Monica Kavanaugh bought 800 cups at the Tim Hortons in Edmonton's Royal Alexandra Hospital on Thursday.

"It's a way to give back," Kavanaugh told the CBC. "They've (hospital staff) helped my father a lot, and I just feel, why not give a little back to the hospital?"

Earlier Thursday, someone paid for the next 500 cups at the hospital Hortons.

It's all great business for Tim Hortons, but the company says it's serendipity, not a marketing stunt.

"As brilliant as this is, I can assure that Tim Hortons has nothing to do with the Good Samaritans that have been purchasing coffees across the country," Tim Hortons representative Michelle Robichaud told CTV.

"We're just as surprised and thrilled as our guests have been by these incredible random acts of kindness," the CBC quoted Robichaud as saying. "Our only role is really in pouring the cups of coffee."