TWO OF TV'S BIGGEST CROWD-PULLERS - soap opera and gambling - combine next month in Cadbury's 'Watch and Win Lotto' - a £1m TV lottery promotion linked to its sponsorship of the evergreen soap, Coronation Street. Each four-times-weekly episode through February and March will feature four winning lotto numbers in the midway commercial break. There is a different winning combination for each episode which viewers will be invited to match against numbers printed inside the wrappers of Cadbury brands such as Dairy Milk and Whispa. The combination for each episode will match five of the wrappers in retail circulation, each worth a £25,000 cash prize. Three matching numbers win £10; and one or two matches receive discount vouchers redeemable at Granada outlets. Total winnings over the promotion's two months lifetime could top £1 million. The potential blockbuster was created by marketing agency Triangle Communications.