Offer easy tips for any problem and your readers will return every time they need some advice.
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.
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.