Links are hugely important for the web.
In a macro, 30,000-foot way, links are the currency that help search engines evaluate the essence and quality of content. They help search engines determine the authority behind a web page.
On a micro level, though, from the reader’s perspective, links also serve as one more of these landmarks that stand out for the reader as she surveys her media landscape.
And when you have mere minutes to woo a potential reader, you do whatever you can to make your page stand out.