The standard approach to interface design is to craft a channel that allows you to easily and efficiently control hardware or software; it’s all about the interaction between people and computers. But today, the two entities on each side of the user interface are changing: it’s no longer about people interacting with computers, but rather about people interacting with people through computers.
This is the nature of the social Web. Social news websites, message boards, social networks, online stores and blogs all have some sort of user interaction going on, whether it’s comments on a blog post or social games on Facebook. The critical issue here is that people are not interacting directly with other people; rather the interaction occurs through a user interface. The computer acts as a mediator.