Customer review

A customer review is an evaluation of a product or service made by someone who has purchased and used, or had experience with, a product or service. Customer reviews are a form of customer feedback on electronic commerce and online shopping sites. There are also dedicated review sites, some of which use customer reviews as well as or instead of professional reviews. The reviews may themselves be graded for usefulness or accuracy by other users.

History
Before the advent of the internet, methods by which customers could review products and services included customer comment boxes and customer service helplines. These methods are still in existence today although internet review sites have grown significantly in recent years.

Reliability
The reliability of customer reviews has been questioned. Abuses akin to ballot stuffing of favourable reviews by the seller (known as incentivized reviews), or negative reviews by competitors, need to be policed by the review host site. Indeed, gathering fake reviews has become big business. In 2012, for example, fake book reviews have been revealed as significantly affecting ratings on Amazon. In 2016 Amazon banned the practice of reviewing complimentary products, researchers have shown that the process still continued as of 2021, but without any disclosures.

Since few sites restrict users to reviewing only items they have actually purchased, it is difficult to know if a customer is real, has actually used the product they are reviewing, and is giving honest, unbiased feedback about the product or services being reviewed. Tools like Fakespot and ReviewMeta can help spot fake reviews on shopping sites like Amazon. Unfortunately, the tools do not work on most other websites that show customer reviews.

Public calls have been growing stronger, demanding that review sites be held accountable for publishing fake reviews. Most recently (June 2021), the Competition and Markets Authority (CMA) in the United Kingdom has launched an investigation into whether Amazon and Google are doing enough to prevent fake reviews from being published on their sites. Both businesses claim to have sufficient resources and policies in place to prevent fake reviews from being published. Legal steps could be taken against the giants if CMA determines those claims to be false.

Whether a customer receives an invitation or not, many businesses have expressed the wish that customers let the business know in the moment if some aspect of their interaction or product is unsatisfactory, so they can have the opportunity to fix it on the spot or provide compensation, rather than customers leaving unnecessarily disappointed and writing negative reviews.

Fake review scandals
In 2010, British historian Orlando Figes posted reviews on Amazon praising his own work and criticizing that of his rivals.

In August 2012, The New York Times revealed that John Locke had paid an online service to write reviews of his books, in order to artificially boost sales.

In 2022, researchers from UCLA documented that millions of Amazon sellers purchase fake 5-star reviews through private Facebook groups.

Spoof reviews
Humorous customer reviews are common on some major shopping sites, such as Amazon. These are often ironically or sarcastically praising reviews of products deemed kitsch or mundane. Another example is methylated spirits described in the style of a wine review. A product may become an internet meme attracting large numbers of spoof reviews, which may boost its sales. Famous examples include Tuscan Whole Milk and the Three Wolf Moon T-shirt.

Examples of spoof reviews include:
 * A Million Random Digits with 100,000 Normal Deviates (book)
 * f.lux (display color adjustment software based on the time of day)
 * Osama Bin Laden's Hideout Compound (humorous reviews of Osama bin Laden's hideout compound written by Google Maps users after his killing on 1 May 2011)
 * Uranium Ore
 * "BIC Cristal For Her Ball Pen"

British spoofers have targeted several build to order novelty products made by Media Storehouse from two million licensed photo library images, including a canvas print of minor celebrity Paul Ross, and a jigsaw puzzle of Nick Humby, a former finance director of Manchester United.