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.
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.
Don't just type, talk to your audience. Blogging is way big a market on internet and people will like you if you do more than just providing information. Suggest, express, appreciate, criticize and have an opinion to build a relativity to a like minded audience. Make them feel that their visit to your blog matters to you.