Here’s how holiday shoppers can avoid falling for fake Amazon reviews

Buyer, beware — that last-minute stocking stuffer from Amazon may not have earned its five-star rating legitimately.

Amid the explosion of e-commerce, shoppers are turning to online reviews instead of ads to decide what to buy. Fifty-five percent of people always use online ratings and reviews to inform their purchase decisions, according to a Better Business Bureau and Nielsen survey.

But sometimes those reviews are bought and paid for, just like advertising.

“The reality is with certain categories of product, buying out fake reviews is actually considered a marketing expense,” said Renee DiResta, director of research for cybersecurity firm New Knowledge.

The dominant e-commerce platform remains Amazon, which sells hundreds of millions of products, with more than half of items sold coming from third-party sellers. Shares of the e-commerce giant are up 40 percent this year, and the company’s market valuation briefly reached $1 trillion in September.