In the virtual world, we simply doesn't know one's appearance (Unless he or she posted a big picture on his or her blog...). I think, we have the first impression from the website visual.
You may think that's impossible! How can I judge someone with a web layout. It simply is words and pictures! But I need to tell you that we can really judge someone from his or her web(now I will use blog as an example).

This is a blog of a Japanese model. I think the impression of her blog is sweet and cute. Not talking about her picture, but the whole design (the dots pattern, the color matching) are quite girlish. We simply will not think that is a boy's blog, right?

Another example is a Taiwan drawer's blog. You will not know what gender he or she is. But you can simply find out that the person is really creative and with good sense of drawing. Also, the blogger play effort on the blog!
Visual elements are important to a web. It just like the first impression we made in reality.
This is what I learnt and apply. Hope you guys enjoy my writing :D