What country are you located in? For residents of the United States, craigslist.org is a popular choice. Canadian residents frequently turn to kijiji.ca. If you do not want your chickens to potentially be used as food, you might want to pursue personal connections as a way to sell them instead. Printing out flyers and putting them up at feed or general store bulletin boards is another way to get the most eyes on your birds. Put effort into your ads, do not simply say that you have "chickens for sale." I have had the most success when I use buzzwords such as "free ranged," "heritage breeds," and "hand-raised." While I would rather present simply the facts in an advertisement, people respond to flash and glitter. Be truthful, but be descriptive. Include photographs, too; I cannot overstate the importance of a high-quality photograph in getting people to look at your ad.
