As far as I know there are two basic business models for that. Monetized content. Product reviews, email courses. etc.
coupon/deals search engine. Some people have worked out special deals with amazon sellers to promote limited promo codes. Honey is a chrome extension that finds coupon codes.
The problem with all of that is it's highly saturated.
So, you really need to think about what your going to create content about and how is it different.
Can also be used as more of an add on for your products.