Because of these blurred lines, Gap last week said it will expand its online and offline synergies, including the ability to reserve items in-store at all domestic Gap stores. American Eagle will also debut the ability to buy online and ship from the store, while Kohl's will grow its ability to ship Web orders from 200 to 500 stores. Wal-Mart is also testing delivery and pickup of its online grocery orders through Walmart To Go.
Read MoreOutlet model may not add up for retailers
But these innovations are not restricted to individual retailers—developers are also getting a piece of the action. Caruso Affiliated's The Grove property offers a free concierge service, where shoppers can call up, request an item, and have it packaged and sent to their home, free of charge.
Four major mall operators, including General Growth Properties and Simon Property Group, are incorporating—and investing—in same-day delivery service Deliv. Through the program, malls fund and supply runners, who collect packages from their tenants and deliver them to shoppers for $5. Customers are able to define a delivery time window that's most convenient for them.
The system gives bricks-and-mortar stores a "huge" advantage over Amazon, Deliv CEO Daphne Carmeli said. It positions the retailers' physical footprints to serve thousands of distribution centers, which allows for faster and more convenient delivery options. By comparison, Amazon only has distribution centers in 14 states.
"You can see how the scale has suddenly shifted," Carmeli said.
What's more, Mathrani said the use of bricks-and-mortar stores more as distribution centers could have deeper implications for retailers' profitability, as it will likely lead to better inventory management, fewer markdowns and higher margins.
"If they can actually get their online inventory and the store inventory to be transparent on a real-time basis then imagine what can happen," he said. "We're just on the one yard line with 99 yards to go."
—By CNBC's Krystina Gustafson.