It was only last month, however, that the company started promoting it in a big way - trying to get young people to register their prints.

A big customer concern is security. Is it safe to trust your fingerprint, a very private and unique identification, to a commercial company? Can the print be copied so that others have access to one's bank account? What will happen to the print? What if the database is stolen?

No worries, everything is fine, the company says.

In the past few years, many companies in Shanghai decided they wanted to keep track of employee attendance and working hours, so they installed fingerprint-recognition devices. The device may take a while to recognize the print. If the finger is wet/sweaty, hurt or pressed differently, it may not register.

Employees are required by their employers to register their prints in a database. The attendance device compares prints.

Pay by finger uses the same technology to compare numbers calculated for 40 points on each print - it actually compares the relationship between points.

The technology was used for national security and military purposes before it was used commercially in 2005, says Gary Chen, senior marketing manager of Live by Touch.

"Each time you press, there's a different set of numbers, depending on how hard you press and at which angle, but the internal logic is the same. So it is very secure because nobody can recreate how your print looks like from the numbers," says Chen.

In early June Miss Zhao, the finger-paying wannabe, registered her fingerprint to establish a link with her debit card from China Merchants Bank.

The purpose was to take advantage of a cinema promotion: watch "Transformers 2" for only 1 yuan (15 US cents). The average ticket costs about 80-100 yuan. "So the promotion is an irresistible deal," she says.

The promoter subsidized the tickets.

Another attractive deal is a huge discount of a popular chain Japanese all-you-can-eat restaurant, which usually costs 160 yuan per person. After registering your print, you can take advantage of the special, one time only.

The discount depends on the date. For example, it's 10 percent of the original price on the 1st, 11th, 21st and 31st - dates containing the number 1. It's 20 percent on the 2nd, 12th, 22nd, and so on. Again, the promoter subsidized the meals.

The cinema and buffet finger discounts were popular. Long lines waited outside cinemas for on-site registration. The discounted seats in the buffet were booked two weeks in advance.