We have seen recent changes on Amazon product review policy and we heard and read a lot of articles questioning if we actually get honest Amazon product reviews with free products. Amazon has also changed their reviews algorithm, meaning that now New Reviews, Verified Reviews and Reviews that are most helpful are given more weight. So, personally I’d recommend putting a system in place to ask for reviews from existing customers.
I have written my experience with accelerating product reviews on thewholesaleforums blog. I’d love to hear your experience on this.