InvestmentsTop Global NewsMarketsReal Estate COVID-19 drags WPP net sales down 7.9per cent in March, braces for bigger impact By financialnews_rlv83x - April 29, 2020 0 63 WPP , the world’s biggest advertising company, said net sales fell 3.3per cent in the first quarter, with the impact of the COVID-19 pandemic dragging it down by 7.9per cent in March alone, prompting it to cut more costs.