The New York Times has some interesting data visualisation about the growth of e-commerce jobs and the decline of retail sectors employment (Figure 1). Online shopping accounts for only 8.4 percent of all retail sales in the United States, but it has had an outsize effect on the retail workforce. The Financial Times has a graphical review of the recent stock market sell-off on retail department stores, spurred by mounting concerns about the effects of online competition.
A related question would be what the implications are, not only for retailers and retail-property companies, but also for the financial firms that have given them money, from banks to life-insurance companies. The Economist argues that total amount of capital, both debt and equity, supporting American retailing (excluding Amazon) now exceeds $2.5trn. The hundreds of thousands of jobs created by new online firms have not absorbed the job losses at traditional retailers. At the same time, the new jobs are concentrated in a handful of large cities and tech hubs (Figure 2 from NYT). Examining property data from CBRE brokerage, The Economist argues that some cities with fewer shops per person, such as New York and Seattle, may fare better, but that few parts of the country will be untouched.