The context, meaning and tone of web copy should always determine typographic style. Reading the text in full—or at least understanding what the text might be before styling it—is a pre-requisite. A common mistake is to allow the design to dominate the text: Design for design’s sake, or even worse, fashion’s sake. The text is made subservient to the canvas that the designer wished to paint on the screen.
—Jon Tan.
A really old piece, but I see something new every time I read it.