Amazon is banning most reviews that were written in exchange for a free product

Everyone reads Amazon reviews before they buy something. But some of those reviews have been, in effect, paid for - the vendor of those items may have sent the reviewer a free unit.

And while there's usually no explicit promise of a favorable review, there's always the danger that people won't be completely honest when they review something that they got for free.

Amazon's putting a stop to this practice. The company updated its community guidelines on Monday to ban what it calls "incentivized reviews."

"Our community guidelines have always prohibited compensation for reviews, with an exception - reviewers could post a review in exchange for a free or discounted product as long as they disclosed that fact," Amazon wrote in a letter to customers posted on its site. "Today, we updated the community guidelines to prohibit incentivized reviews unless they are facilitated through the Amazon Vine program."

Amazon says reviews written in exchange for free products make up "only a tiny fraction of the tens of millions of reviews on Amazon."

However, Amazon will not be removing old incentivized reviews, and booksellers will still be able to provide advance review copies of books.

Going forward, Amazon will be emphasizing its Vine program, a program run by Amazon that asks "the most trusted reviewers" to post reviews and opinions about products.

Here's an example of an incentivized review:

Here's the entire letter:

Customer reviews are one of the most valuable tools we offer customers for making informed purchase decisions, and we work hard to make sure they are doing their job. In just the past year, we've improved review ratings by introducing a machine learned algorithm that gives more weight to newer, more helpful reviews; applying stricter criteria to qualify for the Amazon verified purchase badge; and suspending, banning or suing thousands of individuals for attempting to manipulate reviews.

Our community guidelines have always prohibited compensation for reviews, with an exception - reviewers could post a review in exchange for a free or discounted product as long as they disclosed that fact. These so-called 'incentivized reviews' make up only a tiny fraction of the tens of millions of reviews on Amazon, and when done carefully, they can be helpful to customers by providing a foundation of reviews for new or less well-known products.

Today, we updated the community guidelines to prohibit incentivized reviews unless they are facilitated through the Amazon Vine program. We launched Vine several years ago to carefully facilitate these kinds of reviews and have been happy with feedback from customers and vendors. Here's how Vine works: Amazon - not the vendor or seller - identifies and invites trusted and helpful reviewers on Amazon to post opinions about new and pre-release products; we do not incentivize positive star ratings, attempt to influence the content of reviews, or even require a review to be written; and we limit the total number of Vine reviews that we display for each product. Vine has important controls in place and has proven to be especially valuable for getting early reviews on new products that have not yet been able to generate enough sales to have significant numbers of organic reviews. We also have ideas for how to continue to make Vine an even more useful program going forward. Details on that as we have them.

The above changes will apply to product categories other than books. We will continue to allow the age-old practice of providing advance review copies of books.

Thank you.

- Chee Chew, VP, Customer Experience

Disclosure: Jeff Bezos is an investor in Business Insider through hispersonal investment company Bezos Expeditions.