European retailers are developing their own mobile payment options to help capture more data on their customers, reduce the queue length at checkout and deal with the age old costs of handling cash. The latter accounts for over half retail transactions by volume in Britain - is costly for retailers as it needs to be counted and guarded, costs equivalent to about 2.5 percent of takings, compared with about 2 percent for processing cheques and 1 percent for debit and credit cards.