Had the friendly barista been less busy, I would have told her how sorry I was that I just ruined her good mood. My offense was telling her, "No thanks."

I'm pretty sure it was a polite "No thanks," but an unambiguous no thanks, and I could tell it wasn't what she expected. I'd just declined to add a buck to my java purchase to support cancer research and, by the look on her sweet, surprised face, I'm now the biggest Scrooge in the Twin Cities.

I wanted to tell her that I cherish donating money to good causes, that I've lost many family members to cancer and that it's an awful disease. I wanted her to know I'm really not a miser.

I considered having the same conversation when sliding my credit card through at the pet store, where my obscenely indulged 3-year-old whippet (a rescue dog!) had just spent more time, and money, getting pampered than I do.

A dollar to protect precious animals from being euthanized? Um, no thanks.

I said no thanks at the grocery store check-out, too, to a marvelous nonprofit that combats homelessness.

Today, Nov. 1, launches Philanthropy Month, an annual opportunity for Minnesotans to demonstrate our extraordinary generosity. It's a time of year when we get to feel good about giving.

So, why do I feel so bad about a buck?

I turned to Carleen Rhodes, who reassured me that I'm not a bad person. But I'm clearly not a young person, either.

The new world of social-marketing fund-raising -- donating at the counter, throwing in spare change, Facebook posts for cross-country bike rides and 5K races -- tends to appeal to younger givers, said Rhodes, CEO and president of Minnesota Philanthropy Partners. It's an effective way to launch a charitable life in an affordable and meaningful way.

"For younger people, those impulsive requests -- 'My Caribou person just asked me' -- is a way to introduce them to giving in a way that is, frankly, familiar to them," said Rhodes, who has been involved in fundraising most of her professional life.

The strategy can be jolting to those of us who grew up with direct mail pitches we could toss into the trash. "Now," she said, "that cashier is looking at us."

So we want to explain that our giving tends to be, well, more strategic. We support organizations that we feel passionate about, after we've vetted them. We join friends at galas that are important to them. We support our professional organizations. And periodically, we reassess and shift our donor dollars.

But there are 12 people now behind us in the coffee line.

"You are not alone," assured Michael Nilsen, spokesman for the Virginia-based Association of Fundraising Professionals. This type of at-the-counter pitch has "exploded" over the past five or 10 years, he said, for a compelling reason. It raises lots of money for nonprofits trying to break out of the pack.

Rainbow Foods spokeswoman Vivian King said her customers donate anywhere from $10,000 to $70,000 for nonprofits, including the March of Dimes, Feeding America and Toys For Tots. One year, customers donated more than $120,000 to the Muscular Dystrophy Association.

"Our customers are very generous," she said.

But King is aware of the potential for "customer fatigue," which is why the company has shifted to a quarterly appeal for dollars. Cashiers, too, can experience fatigue with these campaigns, she said, as they try also to keep track of coupons and buy-one-get-one-free items.

"They're pretty effective if we do them periodically," King said.

Nilsen also sees the potential for too much of a good thing. "It's cute once or twice, but when you're getting hit every time? We may have seen the saturation point."

The bottom line is that we all should feel good giving in the way we feel most comfortable. But, please everybody, give, and not just this month. It's not like nonprofits, at the end of November, will be screaming: "Stop donating! We have too much money!"

(Check www.givemn.org for ideas).

Nilsen suggested that I assuage my guilt at the check-out line by saying a quick, "It's a great charity, thanks, but I'm giving here and here."

Rhodes suggests that I say a cheery, "No, thanks. I don't think so today."

"But tomorrow," she added, showing heartening faith in me to act a little younger, "you might feel differently."

gail.rosenblum@startribune.com 612-673-7350