Courtesy costs nothing. Be polite when interacting with fellow bloggers and your readers and your courtesy will be visible in your writing.
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.
Variety is the spice of life so spice up your blog now and then.