Several groups have issued conflicting reports on whether Web traffic increased or decreased on Cyber Monday compared with last year.

Nielsen Online said Web traffic to shopping sites on its retail index increased 10% year over year on Cyber Monday, but Hitwise said visits to the top 500 retail sites that it tracks were down by 1%.

ComScore said online spending hit $846 million Monday, increasing 15% from 2007, but overall holiday shopping online had declined by 2% for the season so far.

Nielsen's positive findings may reflect its focus on online retailers, while Hitwise measures traffic to a wider variety of sites, including those of brick-and-mortar stores.

"The growth in traffic to online retail sites on Cyber Monday was better than many people expected, making retailers hopeful that this growth will carry through the holiday shopping season and drive sales," Ken Cassar, VP of industry insights for Nielsen Online, said in a statement Wednesday. "The combination of aggressive holiday sales and incentives, such as free shipping, across many of the major retailers is helping drive a large number of consumers online this year."

Unique visitors to Nielsen's Holiday eShopping Index of 120 retailers numbered 35.9 million, a 13% increase over Black Friday's Web traffic.

The National Retail Federation's electronic division, Shop.org, coined the phrase Cyber Monday to mark the official kickoff of the online holiday shopping season, when many retailers offer special online deals. Cassar said that if the last several year's trends hold steady, online shopping traffic will peak on Monday, Dec. 15.

"It remains to be seen if people have done the majority of their shopping on these two big shopping days to save time, or if they are holding out for additional sales and promotions," he said.

Nielsen said that visits to beauty sites grew 151% on Cyber Monday, compared with the previous Monday, to become the fastest-growing category. Toys and video games ranked second in terms of growth, with a 112% increase on Cyber Monday compared with the previous Monday. Apparel ranked third, with a 58% increase.

Among retail destinations, eBay led the pack, with 10.6 million unique visitors, according to Nielsen. Amazon.com and Wal-Mart ranked second and third, with 9 million and 5.2 million unique visitors, respectively, Nielsen said.

Nielsen and Hitwise noted strong performance by Sears.

Hitwise said its top sites were Amazon, which drew 10.77% of U.S. visits to its indexed sites, and Walmart.com, which drew 8.55%. Target.com drew 4.56% of the traffic, while BestBuy.com drew 3.81%, according to Hitwise.

Amazon's year-over-year Cyber Monday traffic increased 21%, while Walmart.com's increased 6%, according to Hitwise.

U.S visits to brick-and-mortar stores' sites and to catalog sites each dropped by 4% on Cyber Monday compared with last year, while visits to online-only sites rose 5%, Hitwise said.

Traffic to comparison-shopping sites dropped 21%, according to Hitwise.

Shop.org predicted that 85 million Americans would shop online, but it has not released statistics on the number of visitors to its member site, CyberMonday.com. Last year's CyberMonday.com traffic rose 26% over 2006, on the online shopping holiday.

ForeSee Results said that shoppers were less satisfied this year than last year. That conclusion resulted from a poll of more than 250,000 who shopped online between Black Friday and Cyber Monday.

However, online customer satisfaction was higher on Cyber Monday than any other time in November, according to ForeSee.

"It seems that for the first time, retailers have finally met customer expectations for sales and promotions with all of the well-publicized deals that were available Monday," Larry Freed, president and CEO of ForeSee Results, said in a statement released Wednesday. "Whether or not they can continue to use these techniques to satisfy customers while still remaining profitable remains to be seen, and they don't seem to have much else in their bag of tricks."