Today's retailers must think outside the box. Anchor stores like Barnes and Nobles, Target, and Whole Foods are switching their traditional footprint to make waves in urban settings, often complementing residential communities.

The experts, which included Charlotte Strain, senior director of retail at AvalonBay Communities, and Chris Weilminster, senior vice president of leasing at Federal Realty, point out dozens of examples. Case in point: The Village at Shirlington, a mixed-use development in Arlington, Va., that features a vertical, two-level Harris Teeter. One of the first multi-level Best Buy stores landed a spot at Santana Row, a mixed-use masterpiece in San Jose, Calif. And AvalonBay's Chrystie Place in New York boasts the largest Whole Foods on the East Coast.

Anchor stores, however, are no longer limited to grocery stores and other traditional big box tenants. Rockville Town Center in Rockville, Md., sports a 60,000 square foot library as its anchor. The city invested in the project, and the library is a great business generator for the retail stores, Weilminster said.

At the same time, anchors stores aren't always needed to guarantee a project's success. The highly profitable Santana Row features a mix of smaller luxury shops and restaurants without a main anchor. The ultimate keys to success: careful planning (make sure trash odors from a restaurant don't reach apartment dwellers above), plenty of green space, and lively storefronts with outdoor restaurant seating.