Incorrect - there are a few online stores that are massive in...

Incorrect - there are a few online stores that are massive in America.
They're private enterprises so you don't hear about them if you only follow financial news.
However, those who follow online retail will find that these retailers are massive.

www.newegg.com
www.adorama.com
www.bestbuy.com
www.staples.com

and not forgetting the absolute beast in consumer electronics and photographic equipment...

www.bhphotovideo.com

If you've seen the physical B&H Photo Video catalogues, you'll know these guys aren't fooling around.

A few articles on how they're wrestling with Amazon (who are all about cheap cheap cheap) and how B&H Photo Video is selling at FULL RRP and still holding on to a decent chunk sized marketshare. It's pretty amazing how they're one of the low profile retailers who have successfully executed an omnichannel (online retail + physical retail + B2B) business.

http://bloomreach.com/2016/03/bh-photo-competes-in-the-amazon-era/
http://www.bizjournals.com/bizjournals/how-to/growth-strategies/2012/11/bh-photo-battles-amazon.html

Amazon talks big, and is in the spotlight a lot because they're publicly listed and are in the exciting tech space. The other guys are just quietly making good money and remain private-entities and have no plans to go public (other than Best Buy who is already public NYSE: BBY who grew 12% YOY from $25 to $44 today)

http://www.forbes.com/sites/ryanmac...new-billionaire-on-rising-sales/#e02bdc442b2d

Like the poster above me mentioned, Amazon pummels retailers who sell articles at full price. Jeff Bezos' mantra is "Your margin is my opportunity". Guys like David Jones, Myer, JB Hifi, Ted's Cameras, The Good Guys, Peters of Kensington and the likes will be shittin their pants.

Low margin retailers are better sheltered from the storm, and will in fact be toe-to-toe with Amazon because they're already on lean operations. I doubt Amazon prices will be lower than say the computer stores like MSY or Scorptec, for those who shop for electronics and computer parts, as there's almost zero margin on these, all they survive on is through distributor rebates.