Millions of failed home deliveries are holding the internet retailing market back, a leading industry body has said.Interactive Media in Retail Group (IMRG) says that around four million parcels failed to arrive at their intended destinations in the run up to Christmas, while about 24 million didn't arrive on first delivery.The cost of the internet retail industries' postal failures lies in the region of £682 million, IMRG says, with approximately half of the 7.5 million complaints registered annually relating to botched deliveries."It is completely unacceptable," IMRG chief executive, James Roper, commented. "Anyone that shops online will be familiar with the failed delivery cards that come through the letterbox. "If more than one card has come through, the consumer has no idea which product or retailer it relates too," he continued.Mr Roper says that retailers should allow consumers to choose a preferred delivery time, so that there is a greater chance they will be in when their product is delivered. IMRG forecasts that online sales will rise by 40 per cent to reach £42 billion next year, up from £30 billion in 2006.© Adfero Ltd