We study a model where an entrant chooses between online and offline markets to compete with an offline-market incumbent. When consumers buy a product from the online market, they cannot inspect the product's quality prior to purchase. Conventional wisdom and some literature suggest that this feature drives low-quality products to hide themselves in the online market. However, the literature on vertical product differentiation indicates that a firm may prefer to reveal its product quality in the offline market, because quality differentiation helps alleviate price competition. We show that under fairly general conditions the entrant will choose the offline market for not only the highest qualities but also the lowest ones, and choose the online market for intermediate qualities. While the average quality of the online good is lower than the incumbent's quality, the actual quality of the online good may be higher than that.

我们研究了一个模型，在这个模型中，新进入者在线上和线下市场之间选择与线下市场的现任者竞争。当消费者从网上市场购买产品时，他们不能在购买前检查产品的质量。传统观点和一些文献认为，这一特性会促使低质量的产品隐藏在网络市场中。然而，关于垂直产品差异化的文献表明，企业可能更愿意在线下市场展示其产品质量，因为质量差异化有助于缓解价格竞争。我们表明，在相当一般的情况下，进入者会选择线下市场，不仅是最高质量的，而且是最低质量的，而选择线上市场，是中等质量的。虽然网络商品的平均质量低于现有商品的质量，但网络商品的实际质量可能高于现有商品的质量。