#1 Kelkoo

Cost: $579 million

Acquisition date: 26 March, 2004

What Happened: Kelkoo is a price comparison service in Europe that allowed customers to find information on products they want to purchase, including price and seller information. With its acquisition, Yahoo tried to specifically target the individual customers in Europe, by offering advertising options to businesses.

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Fate: The company has lost much of the traction after it was acquired by Yahoo. However, it continued offer the services till finally Yahoo decided to sell it off on 21 November 2008 to a Europe based private equity firm, for an amount which is lower than 1/4^th of buying price.

Kelkoo still operates, offering its service in 12 countries.

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