There is discussion about whether authors need a web presence and at what level. And I think, as with everything, if as an author you hate the deadline pressure and blogging or if keeping more than a shell website or any of that would send you over a cliff, then don't do it. As a fan of analogies, I would compare it to acting. There are some actors who prefer only one medium, be it television, movies, or theater. Some don't do as well in one as they do in the other, and some really enjoy working in each of them.
And while I think everyone published should have a website, and while I prefer websites with content, be it a blog, or updated links, in the end, I don't hold it against authors who have static websites or dinky websites.
But. If an author is willing to put in the time, and enjoys it (at least a little), I think a web presence can be helpful in growing loyal readers. Look, I know that those of us who haunt author websites and hang out on boards talking book talk are a small portion of the reading population. But we are the superfans. (Not all of them, but we are there.) And I have found authors on the web, and then gone and bought their books. Blogging isn't the same as novel writing, but it gives readers a sense of your voice and your storytelling. And it makes me a little more willing to take a chance and shell out some money. So, it seems worthwhile if its something you can/will/want to do.