Just ban it. The only defense for our lives being flooded with advertising is that it helps markets be more efficient.
But the most efficient gambling provider is the one that extracts the most money from its customers. Helping gambling companies be successful is a net loss to society.
By that argument the companies that are 'most efficient' are the ones that extract the most money. Efficiency is a property of both sides of the equation, and by that light I would say the most efficient gambling provider is the one that charges the least money for the most excitement about the result (which is the positive outcome that gamblers are purchasing, essentially). But to me the ill effects on those who are addicted is enough that the advertising should just be banned anyway.