This paper analyzes how the use of mass vs. direct advertising can affect the pattern of price and quality competition in a market where two firms compete with vertically differentiated products. We show that, compared to the casewheresellersemployonlymassadvertising,theuseofdatabaseadvertising based on historical sales records improves the competitive position of the lowquality firm, which achieves a larger market share and can obtain higher profits. As a result, the high-quality firm lowers the supply of quality, which decreases thedegreeofproductdifferentiationinthemarketandtriggersstrongpricecompetition,thusdecreasingitsprofitsandincreasingconsumersurplus. Finally,we show that, although database advertising is more cost-efficient than mass advertising, the market distortion in the provision of quality implies that the use of direct advertising can yield a welfare loss.