Write regularly, neither too often nor too rarely. Two to three blogs a week is a good frequency to maintain.
Engage readers with well-researched and creative blog posts. At the end of it ask questions or feedback from them.
E-commerce bloggers can gradually choose to write curated content from other websites/blogs. That always helps because a buyer will generally not spend much time surfing. He/she will appreciate it if you provide most of what they are looking for.