The adverts may be following you around the internet. Some are for practical things: reusable sandwich wrappers, rechargeable torches, T-shirts. The rest are far less practical: plush toys shaped like cups of bubble tea, teaspoons shaped like shovels, plastic covers for TV remote controls. What unites them all is that, on the face of it, they cost next to nothing. At a time when even your local poundshop has put up its prices, the Chinese online marketplace Temu – pronounced tee-moo – seems to offer every low- to mid-priced consumer item you could ever need. Its “£1 or less” section...