Some of the world's most famous fashion brands such as Prada, Burberry and Armani are branching out into food. Using the so-called experience economy to promote and expand the traditional retail concept is being seen as a crucial step forward in the luxury market. 

Fancy a glass of champagne at Ralph Lauren? A lobster at Burberry? How about breakfast at Tiffany's? Shoppers aren't just entering these stores for the latest designer fashion and accessories anymore – they also come for the food. 

"You can just have a cappuccino here, you can buy a T-shirt for 50 pounds, but then you can spend 2,000 on a dress – it's not being snobby. It's just being approachable in terms of letting the clients see beautiful items," said Peter Sidell, fashion curator at 202 London.

202 London was one of the first in the city to adopt the so-called "concept" store with restaurant at top and designer fashion below. The shop has become an institution since it opened in 2002. Sidell said the client base is diverse – the weekends will be more touristy and more regulars will patronize during the week. 

Retail analyst Samantha Dover from Mintel said combining good food and good fashion is all part of the expanding "experience" economy. In this generation of social media promotion – taking a snap at a designer food destination – can be just as good as buying one of their luxury fashion items. 

"Social media has undoubtedly fueled the experience economy, so to speak. We are becoming so much more aware of our digital personas and we're really starting to construct our online profiles and the experience economy just goes hand in hand with that," Dover said.

Prada's Marchesi 1824, the historic pastry shop in Milan, will be opening an outlet in May. The fashion house bought a majority share of the bakery in 2014 and saw a steady stream of tourists. The closest Prada store is 10 minutes' walk away. For those designer brands wanting to step into this world of fashionable food, Peter Sidell advised that it's vital they get the menu right. 

"I think that is the greatest part of 202 and is the major part. It's 99.9 percent of the reason that people would be here. The food is good, the chef is good, the staff are good. And you need that in a restaurant, those are the combinations."

For 202 London, the key is keeping it fresh – the menu changes every couple of seasons. As long as the combination of food and fashion stays "in vogue," consumers won't have to spend a fortune to get a taste of luxury.