Temu and Shein are cutting back their spending on US social media advertising as they lose an exemption on tariffs for many of their shipments from China and Hong Kong. The online e-tailers, both of which ship low-priced China-made goods direct to US shoppers, had been on an ad spree until recently. But under an executive order from Donald Trump, as of 2 May their sales valued at under $800 will no longer be exempt from US tariffs. Temu and Shein plan to raise product prices next week as the removal of this “de minimis” exemption increases their costs. They…