So where will people shop today that isn't Amazon?
Some of the results from a study by Deepfield are surprising, including the finding that Shopify ranks No. 3 in the company's list of top Internet retailers.
According to Deepfield, which provides technology to track and analyze network performance, some of the top Internet retailers are the usual suspects, like Amazon, while some others, such as Shopify, are more unexpected.
The company conducted a large-scale study of online shopping infrastructure over the past several months, using data from its ongoing study of Internet backbone traffic.
What it has found is that Amazon, of course, dominates Internet retail. About 14 percent of all Internet users interact with Amazon's site every day, nearly double eBay in the No. 2 position at 8.8 percent. Deepfield included Amazon's flagship site and its other smaller Web properties, like MyHabit, in the count.
Zappos and Quidsi, also owned by Amazon, are large enough to be broken out separately. Both fall in the top five in Deepfield's ranking.
The ranking gets more interesting further down the list with names like Shopify and Shopzilla popping up. Shopify, which ranks third with 5.4 percent share, is an e-commerce hosting site that provides a complete Web storefront offering for more than 30,000 sites.
Shopzilla, meanwhile, ranked No. 6 with 2.9 percent of daily Web users visiting the site. Deepfield notes the site originally was a failed Wharton student business plan competition entry, but it has since grown to direct millions of daily online shoppers to the best deals in other online retail sites.
"While most of the Cyber Monday media attention...focuses on the big names in retail, Cyber Monday also represents a major portion of the yearly sales for thousands of smaller web sites," Deepfield's Craig Labovitz wrote. He added that for larger retailers, "Cyber Monday represents nothing short of an all out price war."
The days following Thanksgiving are some of the key shopping times for everything from laptops to tennis shoes. Shoppers , with some 57.3 million people visiting online retail sites. That's an 18 percent increase over last year.
Cyber Monday, the post-holiday occasion when U.S. consumers take their shopping lists with them to the office, is expected to be even bigger. ComScore estimates it should be the heaviest online shopping day of the season, with sales approaching $1.5 billion or higher. That forecast surpasses the $1.25 billion consumers spent online during last year's Cyber Monday.
Excluding auction sites such as eBay, the most visited site on Black Friday was Amazon, followed by Walmart and Best Buy, according to ComScore. Target and Apple rounded out the top five.
According to Deepfield, Walmart, Target, and Best Buy were near the lower end of its list, while Apple wasn't included.