The major factor in malls,. VS Online is, Take amazon.com. When i purchase an item from and shipped by Amazon.com. I get it in 2 days. IE. ( Toaster ) If that product should fail or be dented whatever, amazon will send a call tag pick it up and immediately send me a replacement. Doesn't cost me a single penny.
If i go to Sears for example. Walmart, etc. I spend time money and travel time because they are 38 miles one way for me to go. Not counting the time standing in a dam line with 1 person working in the returns department then going to find the item again, and waiting in line to cash out.
Then one more thing. TAXES. Of course not everything can be bought online, but for the most part, this is why online shopping has taken over. At least online i do not have to walk around a dam store for 20 minutes trying to find an employee when i need help. Even Walmarts is awful for finding help.