Oriental Trading Company, a US catalogue and internet retailer, sells a quirky, inflatable plastic solar system set for $17.99. The blow-up planets that hang from the ceiling are educational and engaging, but at the end of last year customers buying them from Oriental were not happy. They complained in reviews on the company's website that the sun, the eight planets and Pluto would often just not stay inflated. “I opened the package, blew up the planets, hung them in my classroom, and came in the next day to find three blobs of rubber hanging from the ceiling,” wrote one schoolteacher: “Totally disappointed!!!!”

With customers regularly giving the product low scores on its site, OTC contacted the manufacturer. By January its customer service team was able to announce it had worked with the makers to make sure the planets stayed inflated.

Its experience illustrates the evolution of a feature that has become familiar in online transactions: originally an aid to other potential buyers, online reviews are becoming a valued source of direct customer feedback for retailers and manufacturers.