美国麻省理工学院和西北大学的两位零售学教授研究发现，在购物网站上给差评的顾客往往是在该网站购物最多且最忠实的顾客。套用一句法国谚语来说，就是“你最好的朋友同时也是你最严厉的批评者”。由此也反驳了此前流传的“购物网站的差评多来自竞争对手或奇葩顾客”这一观点。
研究人员对某服装公司的 32.5万条在线评价和亚马逊网站 7000多条书评分析后发现，在购物网站上给出最严厉批评的顾客可能根本没有购买正在评价的商品，而只是对该网站的某项服务或品牌有很深的感情。这些顾客做出的负面评价通常都是有关某个新产品与该公司核心产品系列不一致等问题，希望通过负面评价提醒该公司注意市场策略。研究人员表示，这些顾客通常“自诩为该品牌的推广经理”，虽然他们会给出负面评价，但仍然会继续购买该品牌的产品。
People who write negative reviews on websites are often a retailer's most valuable and loyal customers, American research suggests.
Retail specialists at MIT and Northwestern University found the harshest of critics may not have bought the product they were complaining about, but had strong feelings about a service or brand.
The study, which is the first to take an in-depth look at the behavior of customers who write negative reviews online, has disproved popular theories that peeved competitors or oddball customers make the harshest critics.
Professor Eric Anderson of Northwestern University and Professor Duncan Simester of MIT, examined over 325,000 online reviews written by customers of a large clothing company and examined more than 7,219 book reviews on Amazon.com to produce their study, ABC News reported.
They used data collected by the websites that made it possible to match reviews to purchases made.
The experts concluded that a firm's most loyal customers are also their most negative reviewers, or to quote a French maxim, ' your best friends are also your harshest critics.'
Professor Anderson said that no-one had previously looked at the behavior of individual reviewers before and when they told the clothing company they were receiving negative reviews from their best customers, they were shocked.
They also revealed that the harshest critics had not bought the product they were complaining about and around five percent of product reviews were written by people who had not bought the item they disliked so much.
The researchers found that these reviews were also on average much more negative than the 95 percent of genuine reviews by customers who had purchased a product.
After much hypothesising, the marketing experts concluded that reviewers were acting like ' self-appointed brand managers ' who like the company and continue buying from it despite penning a venomous review.
They found that critics were often complaining about a new product that is slightly different from a company's core offering and want to tell a company if they suspect it is making a bad decision.
Professor Simester believes that customers feel the need to lie about buying a product to review it as they are looking for credibility.
He told ABC News that many people underestimate the importance of their reviews, which can have a harmful effect on a company's sales.
He thinks the findings of the research might prompt companies to insist that reviewers have bought a specific product first before giving their opinion on it.
