Customer reviews on e-retailer websites reportedly have a $400 billion impact on global commerce each year, a recent report found.
The analysis from USA Today cited data from ratings software firm Power Reviews that showed 20 percent of online sales were affected by online reviews of those products.
That would translate to $400 billion of the roughly $2 trillion in annual global e-commerce. The impact would grow to $800 billion if, as expected, e-commerce doubles to more than $4 trillion by 2020.
The data also indicated that a product with one review -- compared to those with no reviews -- is 65 percent more likely to be purchased by casual online shoppers. In addition, one-third of online shoppers said that they wouldn't buy something that did not have a positive review.
The findings highlight the disproportionate impact of the small number of customers — estimated to be between 5 percent and 10 percent — that take the time to write reviews.
Another study from Market Track, USA Today noted, showcased the particular significance of reviews on Amazon.com
Those statistics showed that half of all shoppers rely primarily on Amazon for reviews and that 25 percent check reviews on a smartphone while looking at the same item on store shelves.
The paper noted that Amazon's review system can be vulnerable to organized online campaigns, although the Seattle e-retailer countered that it's taken legal action against individuals who posted fake reviews.
Power Reviews, meanwhile, also said that negative reviews can be helpful. Customers tend to doubt the validity of products with entirely excellent reviews; the optimum rating, the firm found, was between 4.2 and 4.4 on Amazon's five-point scale.