Your obsession on top blogs
A good blog is always written by someone who knows what he is talking about. This means that you would be a far more effective blogger if your blog focuses on a subject that you are intimately familiar with. While no one is expecting you to know every single thing there is to know about your chosen niche, you should at the very least be in possession of a bit more knowledge and/or experience than the majority of your readers. Keep in mind that your readers will gradually come to depend on your blog as a source of information that they cannot get anywhere else, and being knowledgeable in your niche would ensure your reputation as a person of authority. Ripping off other people's content is a no no.