These days an increasingly digitally connected consumer is doing even more of her shopping online, and there are a grow­ing number of “for rent” and “space available” signs in front of malls and shopping centers. Those two trends speak volumes about the shifting—and increasingly competi­tive—landscape of online retailing in the U.S. and Canada, according to an analysis of the data available in Internet Retailer’s newly published 2012 Top 500 Guide.

Consider these facts:

• The retail industry grew as a whole in 2011, but e-commerce remains the fastest-growing channel. While total U.S. retail sales as measured by the U.S. Department of Commerce grew year over year about 5.5% to $2.88 trillion from $2.73 trillion, U.S. e-commerce sales grew 16.1% to $194.3 billion in 2011 from $167.3 billion in the prior year. All Top 500 retailers, including those based in the U.S. and Canada, grew sales year over year 20.4% to $180.73 billion from $150.13 billion.
• Amazon again outpaced the market. The No. 1 e-retailer increased its sales 40.6% to $48.08 billion in 2011 from $34.20 billion in 2010. Amazon’s growth rate was double that of the Top 500 as a whole, including Amazon. Without Amazon, the Top 500 grew 14.4%.
• But it’s not just Amazon. Web-only merchants continue to take market share from everyone else. In 2011, Top 500 web-only merchants grew much faster than every other merchant type—about 32% to a combined $73.39 billion in 2011 from $55.68 billion in 2010. Even without Amazon Inc., No. 1 in the 2012 Internet Retailer Top 500, online-only merchants in the Top 500 grew their combined sales by 17.8% to $25.31 billion from $21.48 billion in 2010, a higher growth rate than any other type of web merchant.
• Other categories of web retail­ers also grew e-commerce last year, but not as much as Internet-only merchants. Store-based retailers grew year over year by 14.7% to $64.63 billion from $56.36 billion, while Top 500 catalog/call center companies increased their com­bined web sales about 12.3% to $22.32 billion in 2011 from $19.87 billion in 2010. Collectively, the consumer brand manufacturers ranked in the 2012 Top 500 grew their combined web sales year over year about 12% to $20.40 billion from $18.21 billion.

The fastest-growing Top 500 retailer in the latest ranking is web-only merchant Jackthreads.com, No. 440 in the 2012 Internet Retailer Top 500. The e-retailer, which increased 2011 web sales by about 359% to $20.2 million from $4.4 million in 2010, is on the sales fast-track because the company is focused exclusively on servicing its core shopping audience of fashion-conscious young men. To enhance growth online last year Jackthreads broadened its social media program, adding new features such as a $10 credit for a member whose product Like on the company’s Facebook page leads to a purchase by another shopper. “We added some social tools in 2011 and made it easy to share items through Facebook and Twitter when a shopper is making a purchase,” says CEO Jason Ross.

But not every Top 500 retailer grew its e-commerce channel in 2011. In the wake of an ongoing company restructuring, web sales for Coldwater Creek Inc., No. 134 in the 2012 Internet Retailer Top 500 dropped 29.2% to an Internet Retailer-estimated $136 million in 2011 from $192.1 million in 2011, while a drop in the popularity of a line of athletic shoes contributed to a decline in web sales for Skechers USA Inc., No. 441, of 27.2% to $20.1 million in 2011 from $27.6 million in 2010.

For the first time the Top 500 is available in three forms: print, digital and as part of the all-new and completely updated Top500Guide.com. Information on how to order the fully updated 2012 Top 500 Guide is available here.