Write regularly; not too often or too rarely. Two to three blogs a week is a good frequency to maintain. Depends on the genre though.
Remember that content is the key to a successful blog, Quality scores over quantity in getting audience to your blog.
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.