Scholars argue that serving markets at the bottom of the pyramid (BOP), composed of consumers with low purchasing power, has been offered as a strategic business opportunity. Beyond serving low-end consumers, do BOP firms affect market prices and the strategic choices of incumbent firms? We examine the impact of a BOP firm's potential and actual entry on incumbent pricing behavior, particularly that of high-end firms. We find that the threat of a BOP firm's entry, as well as its actual entry lowers high-end prices and raises low-end prices in the market. We document similar changes in package sizes revealing a potential mechanism through which this impact on prices is manifested. A BOP firm's entry lowers the package size offered by high-end firms, limits their ability to effectively price-discriminate, and leads to lower high-end prices and an overall increase in the volume of sales. The anticipation of a BOP firm's entry increases low-end prices prior to actual entry, as low-end incumbents adjust their package-size strategy. We relate these results to recent theoretical models of mixed markets featuring high-end and low-end firm entry and reflect on what makes the BOP strategy sustainable.