Rlys aim to make a killing from adsK P Narayana Kumar / New Delhi April 22, 2006In what could create a totally new mode of outdoor advertising in the country, the railways are planning to allow advertising on bogies and goods wagons.Railway officials said they believed the ministry had under-exploited its advertising potential and contended that it could actually be worth about Rs 4,000 crore, as compared to the Rs 110 crore earned in 2005-06.