I was listening to Andrée-Anne talking on Radio Canada about her blog, la Celibataire Urbaine yesterday. She really was just writing a journal for some friends, and suddenly people were writing her and she set up an official blog and has 1000 daily readers and now writes a newspaper column, too.
Blogging is a powerful medium, and it can catch anyone by surprise. The moral of the story is to write interesting posts, and you just might end up with a very viral marketing tool.