Blogging is more about you writing your experiences than what readers want to read. To get the right audience, follow your heart and write what you actually go through.
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.
Blog for the fun of it and show character. It is immaterial how many write about a particular subject, it is how you write the matters.