As demonstrated by Gladwell in his book Blink, we can judge someone with as little information as just looking at them. These snap judgments are the reason why the first impression is important.

When someone visits your blog, depending on the font you used, the theme's color scheme, your photo or the things you blogged about, they can and will form an impression of you. It will probably be a stereotypical assessment but since it might be their last impression, that will be what they think of you.

This is the reason why I'm very careful about things I do online. As I said before, the web never forgets so I wouldn't one someone to stumble on my rant on my blog and have the wrong impression.

Every online interaction someone have with you could be their first and last. I suggest you make it a good one.