Shouting to Be Heard in Advertising

Advertising competes for scarce consumer attention, so more profitable advertisers send more messages to break through the others' clutter. Multiple equilibria can arise: more messages in aggregate induce more ‘shouting to be heard,’ dissipating profit. Equilibria can involve a small range of loud shouters or large range of quiet whisperers. All advertisers prefer there to be less shouting. There is the largest diversity in message levels for a middling width of advertiser types: both very wide and very narrow widths have only one message per advertiser. The number of advertisers at each message level decreases with the level if the profit distribution is log‐convex. Increasing the cost of sending messages can make all advertisers better off. A new technique is given for describing multiple equilibria, by determining how much examination is consistent with a given marginal advertiser.