Start talking to these sellers about possible social review items. I say this because Amazon just did a big wipe again. Sellers are spending lots of $ and with no guarantee amazon will leave the reviews up and not flag their product.
Social review benefits:
Can not be deleted by Amazon, provides a direct link to their store/product and is seen by 1000s more because you only see a Amazon review if you click on that product and read them. Social reviews are seen by fan, followers, blog readers, instagram, twitter and FB users.
I personally have a reach over 4000 people socially. Yet any review I ever post on amazon may be actually seen by 5-10 people.