The simple answer is YES you can do it and it's not spamming or violating facebook rules.
I know a guy here in South Africa who's making a killing with amazon products and facebook ads, I asked him about the RIO and he said it has a good RIO (return on investment). He showed me a screenshot on his amazon dashboard and he's making thousands of dollars every month.
But he doesn't send the traffic straight to amazon, he creates reviews on his blog and send the facebook traffic to his blog posts/reviews. He said the reviews that bring him good revenue are the ones that have videos. The best part is that most of his reviews are now ranking well on Google, so this is a really good long term strategy.
Ranking on Google was not his plan and now he's no longer spending a lot on FB ads, he's relying on Google to send him traffic.
I also use a similar strategy, the only difference is that I don't pay for ads, I managed to build a solid following on social media sites and I just create a post on different social sites and BAM, money starts rolling in. Most of my reviews also rank well on Google.
However, reviews are not my main focus. I use my blog to build an email list, sell my products and promote affiliate products as well.
What you're trying to do does work and it's even better as a long term business if you create a blog. Hope that helps.