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.
People come to your blog out of choice and not any compulsion. If you remember this, the rest is not important enough.
KISS - Keep it simple stupid. Always keep your blog simple, organizes upto the point. Do not over-flood with unnecessary posts or irrelevant images and keep your content straight-forward.