Online retailers are coming to the aid of mall owners, helping landlords fill empty space with pickup/drop-off distribution centers and temporary pop-up stores.

It may seem like an unlikely pair, considering e-commerce continues to eat away at brick-and-mortar retailers' profits, but the trend is gaining prevalence in malls around the country. As community shopping center vacancy rates rose in 30 of 77 U.S. metro areas during 2016, according to data from Reis, mall owners are turning to online retailers as allies, the Wall Street Journal reports.

Amazon has been the most active player so far, rolling out 31 pop-up stores in U.S. malls, unveiling its Amazon Lockers in 50 centers, which allows customers to pick up and return packages in person. But it’s not only Amazon — Google and Facebook have both used pop-up stores to showcase new products in malls. [WSJ]