Juglans nigra English or Persian walnut, but thrives best in the warmer regions of fertile, lowland soils with high water tables, although it will also grow in drier soils, but much more slowly. Some soils preferred by black walnut include Alfisol and Entisol soil types. Walnut grows best on sandy loam, loam, or silt loam type soils but will also grow well on silty clay loam soils. It prefers these soils because they hold large quantities of water which the tree draws from during dry periods. Visually, black walnut is similar to the butternut ("Juglans cinerea") in leaf shape, and the range
Two-sided market to invest more in R&D or lower their prices, driving out weaker rivals. As a result, mature two-sided network industries are usually dominated by a handful of large platforms, as is the case in the credit card industry. In extreme situations, such as PC operating systems, a single company emerges as the winner, taking almost all of the market. Platform managers must choose the right price to charge each group in a two-sided network and ignoring network effects can lead to mistakes. In "figure 2", pricing without taking network effects into account means finding prices that maximize the areas of