Pop-up shops are becoming increasingly popular. There's plenty of empty retail space out there that landlords would rather lease out for even a limited time than continue to lose money on it.
Pop-up shops are a great way to turn a hobby into a money-making proposition. You can sell those Christmas or Halloween decorations you make every year. Maybe you're selling your homemade candles or t-shirts on Etsy, but you'd like to see how they'll sell in a "brick-and-mortar" location. Perhaps you're just not sure yet if you could make a year-round business work, so you'd like to try it out.