Popularity information is usually thought to reinforce existing sales trends by encouraging customers to flock to mainstream products with broad appeal. We suggest a countervailing market force: popularity information may benefit niche products with narrow appeal disproportionately, because the...

Two-sided exchange networks (such as eBay.com) often advertise their number of users, presumably to encourage further participation. However, these networks differ markedly on how they advertise their user base. Some highlight the number of sellers, some emphasize the number of buyers, and...