For a mere £60 a year you too can go 'looting' for moist toilet tissue

With only nine shopping days left until Christmas – and on the eve of the most frantic day of consumerism in the calendar – London's streets are heaving with desperate people laden with expensive presents. I was more relaxed yesterday morning, however, as I walked out of a store carrying a bag of gifts for which I had not paid a penny.

"Free" shopping – or legal looting, if you like – is a new retail fad fresh from those masters of innovation, the Japanese. The "priceless revolution" that began in Tokyo with a company called Sample Central has now spread to 26 countries.

The promise of free Christmas presents lured me to the doors of SampleTrend, which has just opened on Goodge Street, a short walk north of London's Oxford Street. But as I soon discovered, perhaps unsurprisingly, there are one or two catches.

First, you have to become a member to take advantage of "free" shopping. Membership costs £60 a year, and entitles you to five items of your choice every month.

Second, it's questionable whether you would actually want to take home some of SampleTrend's products in the first place - never mind put them under the tree for your auntie to open.

I come away with: a can of Scheckter's Organic Energy drink (worth £1.45); a pot of Drink Me Chai Latte powder (£2.15); Men's Fitness Magazine 7 Rules of Building Muscle guide (£9.99); Colgate Plax Multi-Protection Daily Mouthwash (£2.99); and a bag of Kopi Guatemalan coffee beans (£9.00).

Products I forgo include skincare products and pots of Pringles. The shop guarantees that you will take home freebies worth more than your annual membership fee – my "loot" had a total value of £28.57. If I do this well every month, I will end the year with stuff worth almost £350 – and very good skin.

The savings are big, but only on things many consumers probably wouldn't even have considered buying if they hadn't already paid for membership. And being a member isn't just about the perks. By signing up you also agree to becoming a guinea pig. Your age, your wage, your ethnic origin and your interests are all passed on to SampleTrend's third-party clients – the manufacturers who provide their "free" products.

To "unlock" your next month's batch of freebies, you have to fill in a feedback form on each of this month's items. The forms are mind-numbing. Surely with a product like mouthwash you can't really go wrong? But no, the manufacturer would like to know what "you think is the main thing a mouthwash should do".

All the information submitted by SampleTrend's 800 members – they hope to have 5,000 in a year's time – is forwarded to the manufacturers. For the companies, it is cut-price product research service, for the consumer, a chance to get (sort of) free stuff.

SampleTrend's managing director Michael Ghosh says that the shop is all about branching out and trying new things. "We have a sense that our members are trend-setters and opinion formers," said Ghosh, who used to be an advertising and sales director for Disney. "It's a club and we want people to enjoy the experience."

Because of the members-only policy, you don't have to fight the crowds and the shop floor is designed like a poor man's Apple Store, with minimal clutter and ambient music, presumably to lull you into suggestibility. Then you're reminded that products include moistened toilet paper. I am told SampleTrend is part of Andrex's attempt to change the current perception of wet wipes as something you only buy if you have "problems". Trendsetters and opinion-formers, form an orderly queue.