This study looked at how firms in a competitive market make decisions based on private information about customer demand. They found that if goods are similar, firms benefit from sharing information in a price-based competition (like between supermarkets) but not in a quantity-based competition (like between oil companies). However, if the goods complement each other, it's the opposite: sharing helps in quantity-based competition but not in price-based competition. The study also discovered that overall, sharing info leads to better outcomes in quantity-based competition, where firms set prices first. Plus, sharing info improves efficiency in competition based on prices. Interestingly, while private information is valuable to individual firms, its societal value can differ: it's good in quantity-based competition but not so great in price-based competition.