Adding to what Jura wrote, it's supposed to impress people that a lot of people have purchased the product. Since everyone is buying it, it must be good!

i think it lies in accounting cycle. which related to the deal between customer and saler. record sales like product sales to whom, their addresses, phone numbers. and who is the best customer for a company.

Hi Mitra. "Record sales" = an exceedingly high number of sales. Higher than average.