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.
People come to your blog out of choice and not any compulsion. If you remember this, the rest is not important enough.