Some of Metro Detroit's pop-ups have been so well-received that some single-day dinners, such as those offered by Komodo Kitchen, sell out of meal tickets weeks in advance. Most owners have to tweak their menus after the first day to accommodate a larger-than-expected client base.
The high demand comes with the nature of pop-ups, owners say.
"It's ephemeral; it's fleeting," said Foster, owner of West Village's Coffee and Donuts, which sold out of doughnuts within the first few hours of opening. "You want to see it before you miss it."
For many, pop-ups offer a chance to test a business model.
"It's a good way to act as a litmus test to see if something works out," said Aaron Wagner, co-owner of Tashmoo Biergarten, which sells Michigan craft beers beside food trucks offering sausages and ice cream. The weekend event has drawn more than 1,000 people a day. "There are financial benefits, you're not tied to a year lease, and you can see how your idea works."
There are, of course, some setup costs, and pop-ups do have to obtain a temporary food service establishment license and a certificate of compliance from the local health department.
Wagner and Foster, a former pastry chef who once worked for the Ritz-Carlton in Washington, D.C., want to make their businesses permanent and say they'll base their decisions on how sales go during the next few weeks.
While pop-ups are a testing ground for would-be entrepreneurs, they also serve as trial runs for communities.
Michael Forsyth, a spokesman for the Detroit Economic Growth Corp., a nonprofit that works to bring businesses to the city, said the temporary businesses show neighborhoods what they've been missing.
In West Village, for example, Foster's Coffee and Donuts is renting space at the former Harlequin Caf? and Hillis Apothecary in the Parkstone Apartments building. Next door, a pair of entrepreneurs have opened an apparel shop, PRAMU. The spaces, long vacant, were rehabilitated to accommodate the pop-ups and will soon house permanent shops, Forsyth said.
"The end goal is full-time, full-paying tenants," he said. "The neighborhoods in Detroit have tremendous potential from a retail standpoint. The demand is there from both sides, and pop-ups are a great solution to getting there."
Forsyth recently launched Revolve Detroit, a program to help finance and encourage pop-ups across the city.
"In Detroit, entrepreneurial demand is through the roof," he said. "DEGC is trying to connect the entrepreneurs with the space."
Pop-ups also can create a sense of community.
Tashmoo Biergarten encourages neighborhood residents and guests to drink together — and linger — at long wooden tables — like those at biergartens in Germany. Board games encourage interaction.
Small talk also buzzes at Foster's coffeehouse.
"No one person has walked in here with a book or a magazine," she said. "People have phones, and they don't even get them out. No one's brought in a laptop. Everyone's just having conversation."
Foster's shop will remain open seven days a week until mid-November. She runs the shop herself and already has logged many long nights, but she says it's worth it.
"All night that I'm baking I know I'm going to sell these things, and people are going to be excited," she said. "I really wanted to give my neighbors something they were looking for."