This video explains how to obtain reviews using sites like amzdiscover with a careful approach and what is the caution you must practice.
The purpose of these websites is to do a reverse lookup of the reviewers you find on any ASIN. For example, you sell iPhone X cover. If you approach someone and ask him to give a review, that person may not have any interest in your iPhone X cover since he never uses iPhone. This reviewer won’t reply you.
So what we do is find a top ranking iPhone X ASIN with 1200 reviews on it. Now we give this ASIN to amzdiscover and it will run a reverse lookup to find out how many of these 1200 reviewers are identified in their own database. And you may find 400 of them been reversed lookup successfully. However, amzdiscover will charge you to disclose their email, FB profile, LinkedIn profile, YouTube profile or Instagram profile details etc. with the highest package we take it may come to roughly 6 cents per look up.
Now out of these 400 known reviewers, we want to deal with less ranking reviewers. Very high ranking reviewers may not bother replying you back since they get plenty of queries on daily basis. So go for mid-tier or low tier reviewers. Send a message to 100-200 at least to get a reasonable response coming back.
Do not ever say you want 5-star review because this is where things become non-compliant. Amazon is aware of such services however they keep their eyes close as long as you are messaging them and asking them for real honest review only and keep the product for free in order to give me a real honest review. We never say 5 stars, we never expose our product detail to them so quickly, we never send email from amazon registered email but send from another of your Gmail just for extra precaution.
It is not white. It is not black. But grey area. So we need to do this with enough precaution. And this method can potentially get you 40-50 genuine reviews that you are looking for.