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.
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.
Search engines don't spare any blogger. E-commerce bloggers must keep in mind the search engines in mind while writing blog posts. SEO friendly writing improves the search of your blog content.