Main thing about Successful Blogger - Quality Content
It's been proven and well known that there is no better SEO then to write down original and quality content. You may think this has nothing to do with growing your traffic, but the impact can be substantial. Visitors come to your site to find and read information. If they like what they see, either they are going to subscribe to your RSS feed or enter their email address in the subscription form.
What they expect is more of the same quality of content from you. They have high expectations. It is your job to deliver that to them.