TAIPEI, Taiwan – While no-cashier convenience stores are being introduced slowly to U.S. consumers, staff-less stores keep popping up in Asia.

Last week 7-Eleven Taiwan opened its second unstaffed store, following the January launch of its first staff-less “X-Store” located in inside the headquarters of President Chain Store Corp., which operates 7-Eleven stores in Taiwan.

The store uses facial recognition technology to let customers enter the store, check out and pay for merchandise. In addition, store technology provides “icash” services, smart voice interactivity, self-service POS systems, robot greeters, robot sweepers and more. The staff-free location is an experiment, according to Taiwan News.

A 7-Eleven Signature store opened in Seoul, South Korea, last May, according to Inside Retail Asia. It identifies customers not by the face but by biometric technology that registers the size, color and shape of the veins in an individual’s hand.

Last July, NTUC FairPrice, a cooperative with more than 160 c-stores, converted its outlet on the campus of Nanyang Polytechnic in Singapore into a no-clerk, no-cash operation.

In order to shop there, customers must download and register on the "Shop It Yourself" mobile app, which generates a unique code permitting entry into the store. Inside, shoppers can select food and beverages from vending machines.

In China, BingoBox launched in 2016 and has already been installed in more than 300 locations in 30 cities, according Kiosk Marketplace. Described as a cross between a convenience store and a vending machine, BingoBox uses image recognition and “machine learning” to calculate each customer’s purchase.

Three years ago, F5 Future Store was founded in Guangdong, China, as a 24-hour, no-clerk outlet featuring fresh food, canned beverages and hot coffee served from separate vending machines, reports Caixin.

Shoppers order from a computer screen of product photos, then click and pay for the purchase. Goods are delivered by a robotic arm, which also cleans the store’s dining table when customers leave.

One benefit of clerk-less stores is that employees are free up to focus on ensuring optimal stock and supply. But industry experts say two factors will determine whether they succeed: if shoppers are well-behaved and if the cost of store technology can be reduced.