Late Tuesday, research firm comScore (SCOR) reported that online holiday spending tumbled 3% from the previous year, marking the first decline in seasonal spending since comScore began tracking the data in 2001. "The combination of having 5 fewer shopping days between Thanksgiving and Christmas and the severe economic headwinds faced by consumers has made this a really tough season for retailers, both offline and online," said Chairman Gian Fulgoni.

Checking in on specific e-tailers, eBay (EBAY: sentiment, chart, options) weighed in as the most heavily trafficked site, with 85.4 million visitors. However, eBay's number was actually down 3.9% on a year-over-year basis. Target Corp. (TGT) also saw a traffic slump, with visitors down 1.1% to 46.8 million.

A number of sites fared better by racking up yearly improvements in holiday-season traffic. Amazon.com (AMZN: sentiment, chart, options) welcomed 76.2 million visitors, up 7.4% from a year ago, while Apple Inc. (AAPL) enjoyed a 19% spike to 35 million visitors. Dow component Wal-Mart Stores (WMT) experienced a 3.9% gain to 51.5 million customers.

Despite the mixed results, shares of all these retailers are on the upswing today.