Internet-based product price checking service Kelkoo has been acquired by Yahoo! for about EUR475 million (£317.4 million).
The e-tail company claims that nearly 14 per cent of all European Internet users are its customers.
The Web site enables users to research products online before either buying online or at stores.
A study by AMR Research has suggested that not only is this an increasingly popular method of using the Internet, but people who engage in researching products online also tend on average to spend more.
The acquisition will place the business in a better position to extend into other markets, Kelkoo said.
In a statement, it also said it expected to be run as a separate business unit, meaning the brand and site navigation will remain the same.
'Kelkoo is a complementary extension of Yahoo!'s present advertising opportunities and helps further its position as the largest and most diverse online advertising platform in the world,' Kelkoo said.
'In the short term there will be very little change. Over time we are planning synergy initiatives - combining Kelkoo's price comparison and product feature information with Yahoo!'s other advertiser offerings.'