That Amazon.com review that's influencing your buy? It may not have been written by someone who actually paid for the product. That's because Amazon has an invitation-only program, Vine, for top reviewers—and at least once a month, they get to choose two free products from a list and must review them within 30 days. The reasoning: Products are more likely to sell if they have reviews, even bad ones. NPR talks to one member, currently the No. 1 reviewer on Amazon, who says he's gotten such pricey items as a $500 laser printer and a $1,000 spin bike for free. Michael Erb (M. Erb to Amazon users) has written so many reviews (863 so far), manufacturers have just started sending him stuff directly. But as Business Insider points out, being No. 1 isn't a matter of volume, but the result of a mysterious algorithm that factors in things like quality and helpfulness; in terms of the latter, Erb often goes so far as to include video demos in his reviews. (Here's an example ... for a cardboard box.)
"Literally every other day there's UPS boxes piled up at the door," Erb says. The site can ask for the products back at anytime—though it never has in his five years as a "Vine Voice"—and he can't sell or give away the freebies. One expert says Vine members might be biased toward offering more positive reviews than people who actually paid for their purchases, and The Verge points out that the Vine designation attached to these reviews "wouldn't be hard to glance over." But an Amazon rep says Vine reviews have, on average, fewer stars than non-Vine reviews. Of Erb's last 10 reviews, there are two 3-star reviews, three 4-star reviews, and five 5-star reviews.