LOWER SETUP AND MAINTENANCE COSTS
WordPress is a self-hosted CMS. The only thing you need to pay is the host fee, which could start at a very low price. Apart from the host fee, the software is free to download and use.
There are thousands of themes which allow users to change the look and functionalities of a WordPress website or installation, without changing the information content or structure of the site. WordPress meets the demands of many users with its flexible framework, which allows designers and developers to create and modify layouts as well as applications.
There are more than 55,000 plugins available for WordPress. Users can install different plugins according to their own habits and re-create a highly personalized version of WordPress by themselves.
WordPress supports multiple users working on the same projects at the same time. It enables the user to create a hosted "community" of users and manage them as a group. When working with large blog projects, WordPress is a perfect choice to deal with multi-user issue.
Have a look at SSW Rules to Better WordPress.