Google’s latest ad-powered concept might just tempt web shoppers into retail stores in the future. In a patent granted recently, Google describes an online ad that could offer shoppers a free taxi ride to a retail store to take advantage of potential offers. Restaurants and businesses with brick-and-mortar stores could use the ads to offer free rides to their location and tempt consumers away from rival online competition. The invention involves automatically comparing the cost of transportation and the potential profit from a completed transaction using a number of real-time calculations, says Google in its patent filing.