Does this train station smell like ... grapefruit? How the air around us suddenly became so fragrant.

In 2007, when Spence Levy started selling air — air that smelled good, to be specific — it wasn’t exactly easy.

So Levy trekked along Miami Beach’s famed Collins Avenue, visiting one sprawling white deco hotel after another, asking whether he could pump the scent of green tea, perhaps with a bit of lemongrass, or maybe bergamot or oud, into the lobbies for a week, no charge.