In marketing, a review refers to a written or spoken evaluation of a product, service, or brand by a customer, expert, or third-party source. Reviews are a form of social proof that can influence consumer behavior, as they can provide insights into the quality, performance, and value of a product or service.

Reviews can take many forms, including online reviews on websites like Yelp, Google, or Amazon; customer testimonials on a brand's website; and professional reviews by critics, bloggers, or industry publications. They may also be shared on social media platforms or discussed in person.

Reviews can be an important part of a company's marketing strategy, as positive reviews can help build credibility and trust with potential customers, while negative reviews can provide valuable feedback that can be used to improve products or services.

Marketing teams may actively solicit reviews from customers by encouraging them to leave feedback, offering incentives for reviews, or by providing easy-to-use review platforms. They may also monitor and respond to reviews in order to address concerns or negative feedback and to engage with customers.