Make sure you are interacting with your readers! If you are not doing so, your are not blogging.
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.
Keyword search: Take up a keyword search for the blog posts you are writing. Choose the ones that searched often and have less competition.