One of the hottest trends in retail in 2017 was the pop-up store — a limited engagement retail concept. The pop-up segment was valued at $50 billion in 2016, according to Cushman & Wakefield and Small Business Trends.

Pop-up stores are being used by online retailers to establish an occasional brick-and-mortar footprint. The 2017 holiday season, for example, saw planned pop-up stores from Amazon.com Inc. and Alphabet Inc.’s Google.

CBRE identifies pop-up strategies as one of the 2017 holiday season’s key retail trends, pointing to several factors underpinning the explosion of pop-ups: retailers need for experimentation, holiday traffic and sales opportunities, and increased appetite among landlords. Westfield Corp., Simon Property Group and Oxford Properties Group are among shopping mall owners who have offered pop-up sites.