When you started your blog you had a particular reason for doing so; it might have been to express your views on a topic or it might have been to just communicate with a close circle of friends about your daily activities. Readers will come to your blog for the first time and either be interested in your subject matter or not, will either like your style or not and, if they like your subject and style they may comment and then come back later. Once you’ve established a topic and tone for your blog you’re free to change it but to do so you’re basically starting all over.