We demonstrate that the Varian (1980) model of sales has a unique Nash equilibrium when firms incur costly advertising to compete for informed consumers. The equilibrium is symmetric. In particular, with costly advertising, the asymmetric equilibria highlighted by Baye et al. (1992) do not arise.

We analyze the impact of market share on advertising and pricing decisions by firms that sell to loyal, non-shopping customers and can advertise to shoppers through an information intermediary or "gatekeeper." In equilibrium the firm with the smaller loyal market advertises more aggressively but...

This paper explores the strategic tradeoff between advertising and pricing when firms have asymmetric loyal market segments and also can compete for shoppers who purchase at the lowest advertised price. Two advertising structures consistent with real world settings are considered. In the first...