At almost 92, Gerard Dunn of Sydney, N.S., has received lots of birthday cards over the years. But that's nothing compared to what he's about to get.

He can thank his daughter Miriam Dunn, who on Monday sent out this tweet:

She assumed a dozen or so people would retweet it. She did not anticipate what came next. In two days, her appeal has been retweeted more than 20,000 times.

Responses have been flooding in from around the world, from as far away as Scotland, Spain and Australia.

"They're almost entirely positive. People talking about how much it means to them to see something happy," Miriam said. "Especially on Twitter. Twitter is very divisive in terms of politics right now. So this is something that's joining people together."

Most are promising to send letters or cards — some are even inquiring about Gerard's interests so they can send gifts. Miriam figures if even a quarter of them follow through, her father could be in for thousands of pieces of mail.

Miriam describes her father as a soft-hearted man full of life and joy, who loves to play the piano and sing.

"Since mom's passing, I think it would only be normal to expect a person to be feeling rather alone," she said in an interview with CBC's Maritime Noon Wednesday.

Miriam and her siblings are in the habit of sending their father cards, photos and newspaper articles. She turned to Twitter to "solicit a few people to help out."

"Once it really got big, out of control, I thought I better tell him," said Miriam. "So I did tell him, 'Dad, you're going to receive a lot of mail.' And he just thought that was fantastic. But I don't think he really understands how much."

To help drive it home, she showed him her Twitter feed Tuesday night.

"He was reading through all the positive comments and the warm wishes and all the love being sent out to him. And he got a little teary-eyed. And I have to say that I think he feels that this is more about mom than about him, you know, that it's a tribute to mom's life … So he's very moved by it."