This is an optional step. Depending on your chosen product you may already have plenty of products on your website. However, if there are many different variants of your product and lots of products in Amazon that have plenty of review, then you should add more to your website.
The more products you have, particularly if they are well reviewed products, the more scope you have for writing articles. You have more products to compare against each other, more price ranges to include in specific overview articles.
If you can add 10 more products to your website using the same structure as mentioned here in Step 5.