Angelica Mari, Computing , Monday 10 November 2008 at 11:11:00 Sector will still generate £13bn during Q4, but consumers are buying less Online spending growth will plunge to 15 per cent this Christmas from 54 per cent two years ago, according to a survey carried out by IMRG and Capgemini. Even though cash-strapped consumers are still going online, the survey shows that …