My company's blog does this for related products that we don't personally sell in our online shop. It's good to the tune for $10k/year without trying much, but

My company's blog does this for related products that we don't personally sell in our online shop. It's good to the tune for $10k/year without trying much, but you have to get good at writing the copy into real blog posts, not just random spam. It works pretty well. Conversion rate post-click of about 8.5% this month.