Look!” said the first little boy to walk by with his parents. “Awesome!” the next child, a little girl, said to her mother, pointing at a vast inflatable backyard paddling pool suspended from the warehouse ceiling.

At Costco’s Kirkland warehouse located outside Seattle, the pool dangling from the rafters was presumably apparently delivering what Richard Galanti, the US retailer’s chief financial officer, calls the “wow” factor – that extra bit of retail excitement that it wants to produceso as in order to draw visitors be a central part of the appeal of a visit to its cavernous, no-frills warehouse stores.