It’s like an unified Blog website, thousands of similar client websites rent a large scale platform system. After signing up, there is a management interface for you to manage your website content. Blog is a free to sign up commercial site that requires a rental fee.
Pro: You can promote your website through platform advertisement.
Con: All websites look alike, the visitors can not perceive the differentiations of your products or services. It is only good for presenting information, not improving company image.