The power of the pop-up business

Pop-up comes in all shapes and sizes, be it a restaurant or store. And while each "finite" business—as they have come to be called—may have a fleeting lifespan; the trend is gaining traction on a massive scale.

Take the U.K., the "finite" industry is now worth £2.3 billion ($3.5B) says U.K. mobile provider, EE; while in the U.S., the shops bring in $2 billion during the holiday season alone, says online resource, Pop—Up Republic.

"Pop-up culture helps to test the idea before you go big. Businesses are attracted by it as you can launch something for a week, not get into any lease agreements, keep costs low and test the idea before scaling it," says Sebastian Lyall, founder of Locappy, a London-based start-up app company.

"Consumers love it because it has intrigue. We all like to be involved with unique things that won't be around forever."

For any pop-up, an identity can only survive if its theme is unforgettable, and it is in a prime location — attractive cities help.

Dan Calladine, author of "London Pop-ups" site, told CNBC he receives word of 15 new interesting pop-ups in London every week, with over a dozen PR companies getting in touch.

In 2013, city lawyer, Jessica Tucker launched Urban Food Fest: a pop-up festival that provides Londoners and Mancunians a fresh concept every week.

Every Saturday, 15 food trucks appear, with a brand-new selection of cocktails, food and musicians. Tucker told CNBC that hundreds of thousands have visited and they've expanded to provide a service to corporate clients. When asked by CNBC, Tucker declined to disclose the revenue and profitability for Urban Food Fest.

"We offer world cuisines at extremely cheap prices – with no compromise whatsoever on quality of ingredients or taste. All our street food dishes use gourmet ingredients and have an amazing variety."

Calladine wouldn't be surprised with this success, saying one of the latest popular trends is "street food people taking over pub kitchens".

Analysts often pinpoint pop-ups' "big rise" to 2008: the time of the economic collapse, where finite businesses transformed from something that was edgy and alternative to joining the mainstream, thanks to their low costs and creativity to attract cash-strapped customers recovering from the crisis.

Thanks to its relatively recent popularity, analysts are wondering whether it's appeal is only confined to the millennials.

Paulina Habben, head of community & communications at Go—PopUp, said the industry belongs to millennials, both as customers and entrepreneurs.

"Millennials are receptive to new ideas, new ways of living and shopping," she told CNBC via email.

"Pop-up stores often offer new, exclusive products and unique locations, which is appealing to these consumers. In fact, as the most entrepreneurial age group, a lot of pop-up stores are run by millennials. Traveling and a flexible lifestyle constantly bring them to new surroundings."

Werner van Huffelen, owner of The Design Strategist, told CNBC via email, that pop-ups are great for millennials as they "value new experiences over ownership or possession of products" and the industry delivers that.

"The millennial generation is said to be the most entrepreneurial generation of all time. Being raised in era with more possibilities - than for example their parents - it provides fruitful ground for new businesses. Furthermore it is easier than ever to start your own business. A lot of pop-up stores are the result of successful webshops."

Van Huffelen added that a pop-up's most powerful tool is the "element of surprise" and they should exploit it as millennials are attracted to unique experiences.

Will the trend lose steam? Doubtful, Lyall expects it to catch on elsewhere.

"This culture will expand to many cities around the world in the coming years," he said.

"The base of pop-up culture rests on the abundance supply of empty spaces and shops. The aftermath of recession has assured that in every city, we have places which are empty. These places will be used by pop-up organizers and this trend will grow."

Others, however, say the trend is nothing new.

"Pop-ups aren't a millennial thing: they've been part of our cities since the 1960s, with a strong scene in the 1980s, and a big rise from 2008. Arguably the earliest recorded pop-up is Shakespeare's theater company!" says Dan Thompson, author of "Pop Up Business for Dummies."

—By CNBC's Alexandra Gibbs, follow her on Twitter @AlexGibbsy.