It doesn’t happen all that often, but in one case a column in House & Garden in June 2005 turned into a chapter in a book published in November, 2006. That would be Jay McInerney’s book, Hedonist in the Cellar. Assist a journalist to the best of your abilities and this too may happen to you:
http://dinersjournal.blogs.nytimes.com/2007/08/08/mountain-men/