Ciao was a European-based online-shopping portal with websites in the United Kingdom, France, Spain, Germany, the Netherlands, Italy and Sweden.

[1] The site provided a forum where registered users could write reviews and give their opinions on a wide variety of products to help others make decisions.

These reviews were available to the general public to help consumers, but also rated by other Ciao users on their usefulness on a scale ranging from exceptional to off-topic.

[citation needed] Microsoft made an offer of $486 million in late August 2008 to purchase Greenfield Online, the owner of Ciao GmbH and Ciao, Inc.[2] Representatives from Microsoft said the purchase was primarily made to boost the company's Internet search and e-commerce business in Europe.

[3] Since the acquisition in March 2012, Ciao strengthens the portfolio of LeGuide Group (listed on Alternext board of NYSE Euronext Paris – ISIN code: FR0010146092), founded in 1998 and operating in 14 European countries through a multi-site strategy of online shopping guides, comparison websites, shopping search engines and platforms for consumer ratings.