I came across a interesting article about web design and the use of typography within it. What I think sums it up is this paragraph
“With some imagination (replace print with online) this sounds like the job description of an information designer. It is the information designer’s task “to divide up and organize and interpret this mass of printed matter in such a way that the reader will have a good chance of finding what is of interest to him”
Have a read of Oliver Reichenstein’s article Web Design is 95% Typography here.