A "nightmare scenario" could face grocery retailers as their most profitable customers migrate to their internet shopping arms. This would leave the least profitable casual buyers and bargain hunters to shop in their stores, according to the latest Mintel report on the UK online grocery market. A few big spending, cash rich, time poor customers generate most of a retailer's profits, but the additional costs of servicing them online rapidly makes even the biggest spenders unprofitable, says the report. The findings coincide with research from Verdict which reveals the "huge losses" suffered by retailers developing online capabilities when it is still not clear whether the percentage of groceries likely to be bought online will ever justify the colossal expense. The only way to make any money from internet shopping is to sell large non food items, such as cars and white goods, online, says the report. It goes on to predict that food will eventually become a loss leader to encourage shoppers to purchase items offering retailers better margins. Other e-commerce experts agree with the findings. McKinsey's Douglas Gurr said: "Let's say it costs Tesco between £13 and £15 to pick, sort and deliver an order. They only charge £5, so you have to order an awful lot before it makes economic sense." But steering clear of the online shopping revolution could prove even more expensive in the long run. Despite its recent successes, Safeway is probably already losing some of its highest spending customers to Tesco.com and risks losing even more to Sainsbury and Asda as they roll out their offering, he warns, echoing a passage in the report highlighting the fickleness of grocery shoppers: "The ease with which an online consumer can order from rival supermarkets is likely to weaken existing loyalties." To order a copy of the report, contact Dalwinder Dhillon, on 0207 606 6000. {{NEWS }}