The new service is intended to provide retailers with insights into consumers' online buying activities across retail sites, Web portals, search engines and comparison shopping sites. It will also offer data on Web marketing performance, shopper demographics and behavioral profiles.

Still, Compete faces an uphill struggle building the practice at a time when retailing has been described lately as "falling off a cliff" as a result of the rapidly deteriorating economy. ComScore is predicting that e-commerce sales will grow between 6% and 10% this holiday season, compared to 17% last year and 20% in 2006.

And a new retail survey released Wednesday by UBS and America's Research Group Ltd. found that only 22% of household "decision-makers" will shop online this holiday season, compared to 38% last year. The report overall forecasts the "worst Christmas in recent memory," with same-store sales in November and December expected to fall by 1%, compared to a 2% gain last year.

"It's certainly a trying time for retailers," acknowledged Matt Pace, who leads the new practice. "But it also opens up an opportunity for people to ask 'are we getting the returns we're looking for?' and 'how are we doing relative to our rivals?' That's the kind of information we can provide and let retailers know if they're spending their money wisely or not."

Compete uses a panel of 2 million Internet users to measure online purchasing behavior and the effectiveness of online ads.

Pace said Compete's focus on e-commerce would complement the offline retail-tracking services of parent TNS, which acquired Compete last March for $75 million. In particular, Compete aims to help retailers to improve search marketing and site optimization efforts to drive more online sales.

Its new retail research service will offer two syndicated reports--one that is more focused on individual site metrics, such as time spent and bounce rates, and a more comprehensive offering, covering category and site metrics in more depth.

Pace said Compete would also provide custom reports on topics such as consumer response to a client's redesigned e-commerce site. Drugstore chain CVS is among Compete's retail industry clients.

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