Places like Yelp, Urbanspoon, TripAdvisor and Google Places are extremely helpful when trying to bring in business and traffic to your site. It's also important to understand what users are looking for when they are browsing for content. Most users are looking for something interesting or they want to purchase a product or service that is exclusive to a market. With SEO and directories, you can make your site stand out and even become more readily available than your immediate competition.
For example, Web.com uses directories as part of their marketing package for business customers. In addition, directories are also frequented by users who need instant gratification. They thrive on being able to look at reviews and maps to see where your business is located and find your business within the values of their search. If you're listed in a directory, it will enable your business to become more successful in the long run.