I use Craigslist a lot when I do a retail store closing sale. It is a great way to promote the sale when the sale prices are 50% off or more and especially for selling fixtures and bulk products. These same methods would work with a retail store doing a sale.

For selling products, I generally use under For Sale:
General Category , Garage Sale for Saturday events and a specific category depending on the merchandise being sold. I take pictures of entire departments for customers...