Online retailers are defying the odds by expanding their physical footprints and real estate developers like Simon Property Group, GGP and Taubman have begun to take notice with many offering incentives to lure retailers to formerly vacant spaces.

The success of these offline expansions, which were first tried by the likes of eyeglass retailer Warby Parker, which will reach nearly 100 brick-and-mortar stores this year, could be in part attributed to how starting online allows retailers to be more strategic about their real estate decisions later on. Companies can look to online databases to determine where their most loyal customers are based before setting down roots in any one market. But many of the retailers are also more flexible than those in the past and are willing to test out pop-up shops, smaller stores or even move around more frequently, CNBC reports.

With developers and landlords becoming more open to offering pop-ups and short-term, flexible leases, online retailers have been able to test offline concepts without too much risk.

Retailers including apparel company Everlane, mattress firm Casper and bedding company Boll & Branch are among the online companies finding success by joining the brick-and-mortar movement.