Reach Out to Sellers and Offer Your Review
The first way to get a free Amazon product is to negotiate a deal with sellers directly.

To do so, just follow these steps:

Log into your Amazon account
Search for something you want on Amazon
Scroll through the search results until you find a listing with few to no reviews
Message the seller
Tell them you'll give them an Amazon review in exchange for a free product or gift card
There are hundreds of thousands of sellers that will take you up on this deal. They understand that a five-star review will help them more in the long run than your money. Thus, it’s a win-win for both of you.