Often, when a retailer decides to close a store, it's because it's located in a struggling mall. According to Green Street, the U.S. is home to 1,100 regional and "super-regional" malls, which tend to be larger and offer more variety. Yet as the firm's research shows, not all malls are created equal.
Whereas the top malls rake in roughly $965 a square foot, those on the other end of the spectrum bring in just $130 per square foot. All in, Green Street estimates the top 300 malls account for 75 percent of the sector's value.
"[Net operating income] growth should be healthy for higher-quality malls, but lower-productivity centers should struggle due to softening retailer demand and the 800-pound gorilla ... e-commerce," Busch said. "Several will go dark."
Though the shift to online shopping is no doubt playing a role in lighter foot traffic at malls, there's more to their changing economics than the rise of Amazon. Changing demographics in a town are another reason a shopping center could struggle or fail — for example, if massive layoffs in a particular industry cause people to move away to find employment.
"A lot of people want to try and tie it to the Internet or 'that's not cool,' or teens don't like it," Jesse Tron, a spokesman for industry trade group International Council of Shopping Centers, told CNBC last year. "It's hard to support large-format retail in those suburban areas when people are trying to just pay their mortgage."