I love this one:
"Aaron Durand’s mother was in trouble. She had run an independent bookstore for nearly two decades when an economic downturn hit that threatened to close the shop. Aaron wanted to help his mom, but wasn’t sure what he could do. He wrote about his mom’s plight on his blog then tweeted it out, adding at the last second an offer to buy a burrito for anyone who bought $50 worth of books during the holidays at his mom’s shop.
The story took hold. The Tweet was passed along from person to person across Portland’s art and design community. It was retweeted and retweeted until hundreds of people had read the story.
Overnight, new customers started to arrive and business began to pick up. The story continued to snowball on Twitter. The bookstore went on to have its best holiday season ever, and has continued to thrive each season since."
(Doesn't always work, of course...)
See the stories here