E-commerce bloggers must carefully write keeping their audience in mind. Everything you post on your blog will speak for your product or service. Your interaction with bloggers in comments and otherwise will give you a direction.
Originality - Focus more on the originality of content and on a consistent basis. It is a habit you will need to cultivate.
Series of articles - Create a series of articles on your blog if the subject you choose to talk about is an extensive one.