I often visit the sites of other writers and literary agents to gain insights into the business of writing. However, it's essential not to lose sight of the end game--the sale to the consumer. I'd like to recommend Bookseller Chick's site. In addition to posting with a great sense of humor and wit, she sees what and how people buy in her bookstore. For example, check out her insights on Romance Covers and Spray On Ethnicity.
And when you stop by, please be sure to say hello!