In the November 2005 Fast Company magazine, there is a good article about the power of simplicity. What I really like about the article is that it captures what I believe to be the hallmark of good design: Making the complex simple. This is good, not only in industrial design or product packaging, but it is also good for communication design.
The choice of medium is not the issue. The medium can be a website, print ad, flyer, or brochure. The design of simplicity is a product of thought. The medium shouldn't dictate the thought. However, the thought should dictate the medium.
For example, a person wants to get some items at the store. What mode of transportation they use is a result of many factors: Do they own a car? If not, what are the alternatives? Can they shop for the items online? How fast do they need the items? Etceteras.
What people do not typically do, is to start walking out the door for some items without considering why or where they are going. People tend to have at least a vague idea of where to go to get the items they need.
So simplicity is a planned process, not a product "feature" or page decoration. As always, good design starts with the audience (or end-user), the goal, and the method in mind. Armed with these considerations, good design is the process of taking seemingly unrelated pieces of information or facets and bringing them together into clear communication or product.
Remember, the end goal of simplicity is not lack, but rather knowing when enough is enough. As Milton Glaser says, "Less isn't more; just enough is more."
This is the 10th out of 11 articles discussing, in detail, each point in my philosophy of design. My philosophy is discussed in my previous post.