According to Black and WTF:
Overstocked with a large supply of men’s spring and winter coats, a clothier in Copenhagen, Denmark, adopted a unique sales scheme. He erected a scaffolding around his store building and completely covered it from roof to sidewalk with more than a thousand overcoats. The novel display attracted prospective customers in such droves that police were summoned. Although the police ordered the proprietor to remove the display, he succeeded in selling all the overcoats.
The date is unknown.