There are a variety of web sites and browser plug-ins that will tell you if their algorithms detect fake reviews though I rarely use them. Here's one that I have found to be relatively useful: https://reviewmeta.com/
Generally, the products that have fake reviews are low-cost junk anyway and not in the category of things I shop for, so I don't really worry about it.
Almost every company out there makes some effort to solicit reviews (they know that reviews sell), that is not review manipulation so long as they are only soliciting honest reviews. If I am making a larger purchase of an item with few reviews often I will contact the seller and tell them I would like to review their product and ask them for a coupon code. They can look at my past reviews and see that I only post honest reviews. Not everybody offers a coupon code but I often get 10-40% off. When Amazon is ranking the weight of a review one of the factors they take into consideration is the amount of money the buyer spent on the product so sellers are reluctant to give up-front discounts higher than 50% and most of them feel like 40% is their limit.
This company used to be a review manipulation service but has come around from the dark side and now only solicits honest reviews. Most of the stuff is junk but it's worth checking back because every now and then they have a steal:
https://www.vipon.com/
This one operates a bit differently and I've never used it but I know people who have, they sometimes get deeply discounted even free stuff. Because the rebate for the product is given after the purchase and without Amazon's knowledge it dodges the discount ranking problem with coupon codes so in a way is a mild form of review manipulation. People will give higher reviews for something if they aren't paying for it even if they are doing it subconsciously:
https://rebatekey.com/
Generally, the products that have fake reviews are low-cost junk anyway and not in the category of things I shop for, so I don't really worry about it.
Almost every company out there makes some effort to solicit reviews (they know that reviews sell), that is not review manipulation so long as they are only soliciting honest reviews. If I am making a larger purchase of an item with few reviews often I will contact the seller and tell them I would like to review their product and ask them for a coupon code. They can look at my past reviews and see that I only post honest reviews. Not everybody offers a coupon code but I often get 10-40% off. When Amazon is ranking the weight of a review one of the factors they take into consideration is the amount of money the buyer spent on the product so sellers are reluctant to give up-front discounts higher than 50% and most of them feel like 40% is their limit.
This company used to be a review manipulation service but has come around from the dark side and now only solicits honest reviews. Most of the stuff is junk but it's worth checking back because every now and then they have a steal:
https://www.vipon.com/
This one operates a bit differently and I've never used it but I know people who have, they sometimes get deeply discounted even free stuff. Because the rebate for the product is given after the purchase and without Amazon's knowledge it dodges the discount ranking problem with coupon codes so in a way is a mild form of review manipulation. People will give higher reviews for something if they aren't paying for it even if they are doing it subconsciously:
https://rebatekey.com/