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.
Series of articles - Create a series of articles on your blog if the subject you choose to talk about is an extensive one.
1 per day: If you have just started blogging, then writing consistently might take time. So set a target to have 1 post per day that is well researched.