Here's one answer to that question: because a blog is a visual medium before it's a thoughtful medium. People SEE it before they read it. The web was created to be visual. Before the web, the Internet was nothing but text. Talk about boring! Once the world wide web was invented by Tim Berners-Lee, the concept exploded in color, design, and attention.
When you decide to create your blog, it's understandable that you want to create something that pleases you. The colors, the way the blog looks, the images you use, all play into designing a look and feel that makes you happy. And you want to be happy when you blog, right?
You can't stop there, however. You must stop and think about your audience. How will the design make them feel? Is black a good background color? Is red? What about the text? What font should you use? Will the color of the text work against the background color, once a link is clicked?
Don't forget images. Should you have people and pets in your header? Just pets? Just people? The great outdoors? And, what size should they be?
These are some of the questions you need to ask yourself. And, once you've created your blog design, you need to test it with a group of select people. Always ask your Mom! But, don't limit yourself to friends and family. You can't depend on them to tell you the truth. They may be too flattering or too critical. Ask a range of people, and ask them to ask one friend – someone who doesn't know you.
For images, you decide how many but make sure they're optimized. Images that take too long to download will send readers clicking away! You have about 2-3 seconds to get your reader's interest – before they click that mouse and go somewhere else! Don't make them wait for that fantastic shot!
Your design is more than a pretty face to the public. It's a representation of the purpose of your blog and the meaning of your writing. If you're writing a travel blog – show some pets in cars or airplanes. If you're writing a nutrition blog, show off some food, and pets slurping it up. If you're just blogging about everything pets, make sure you have pets in your header – and use colors that are upbeat.
Here are some designs I like. Share some you like. Even better, share some you don't like!